Bio


Dr. Sebastian Fernandez-Pol is an academic hematopathologist with fellowship training in hematopathology and dermatopathology. He has a particular interest in improving diagnostic accuracy for cutaneous lymphoproliferative disorders. Dr. Fernandez-Pol received his B.A. in chemistry with a concentration in biochemistry from the Washington University in St. Louis in 2003, his MD and PhD from Northwestern University in 2013, and completed his anatomic pathology and clinical pathology residency, hematopathology fellowship, and dermatopathology fellowship at Stanford University in 2019.

Clinical Focus


  • Hematopathology
  • Anatomic and Clinical Pathology
  • Dermatopathology

Academic Appointments


  • Clinical Assistant Professor, Pathology

Professional Education


  • Fellowship: Stanford University Dermatopathology Fellowship (2019) CA
  • Board Certification: American Board of Pathology, Dermatopathology (2019)
  • Fellowship, Stanford University Hematopathology Fellowship, CA (2018)
  • Board Certification: American Board of Pathology, Hematopathology (2018)
  • Board Certification: American Board of Pathology, Anatomic and Clinical Pathology (2017)
  • Residency: Stanford University Pathology Residency (2017) CA
  • Medical Education: Northwestern University Feinberg School of Medicine (2013) IL

All Publications


  • Targeted mutational profiling of Epstein Barr virus-positive mucocutaneous ulcer: Implications for differential diagnosis with EBV-positive diffuse large B-cell lymphoma. Annals of diagnostic pathology Volaric, A. K., Kumar, J., Nicholas, V., Saleem, A., Fernandez-Pol, S., Suarez, C. J., Natkunam, Y. 2024; 73: 152344

    Abstract

    Epstein Barr Virus-positive mucocutaneous ulcer (EBVMCU) can be difficult to distinguish from EBV-positive diffuse large B cell lymphoma (DLBCL). We used targeted next-generation sequencing (NGS) to explore genetic alterations in EBVMCU to aid in this diagnostic challenge. Ten cases of EBVMCU were evaluated by a targeted NGS panel of 164 genes. Targeted NGS identified 18 variants in 15 genes in eight cases of EBVMCU. Loss of function TET2 variants were most frequently identified (3 of 10 cases, 30 %). One TET2 variant occurred at low variant allele frequency (VAF) of 3 %, which may be suggestive of clonal hematopoiesis of indeterminate potential. One case harbored a loss of function DNMT3A variant at low VAF. Two cases demonstrated missense variants in the IRF8 gene. Both variants occurred at a VAF close to 50 % and with an estimated high burden of disease (75 %). Two cases of mucosal gastrointestinal involvement had no reportable variants. Mutational profiling of EBVMCU identified TET2 loss of function variants at an elevated frequency in our cohort; however, the findings are not specific and its clinical significance cannot be completely elucidated. Further studies are needed to confirm the findings in an independent and larger cohort of EBVMCU, to determine the cell of origin of the variants, and to further assess their significance in the pathogenesis of this disorder.

    View details for DOI 10.1016/j.anndiagpath.2024.152344

    View details for PubMedID 38820910

  • Engineered CD47 protects T cells for enhanced antitumour immunity. Nature Yamada-Hunter, S. A., Theruvath, J., McIntosh, B. J., Freitas, K. A., Lin, F., Radosevich, M. T., Leruste, A., Dhingra, S., Martinez-Velez, N., Xu, P., Huang, J., Delaidelli, A., Desai, M. H., Good, Z., Polak, R., May, A., Labanieh, L., Bjelajac, J., Murty, T., Ehlinger, Z., Mount, C. W., Chen, Y., Heitzeneder, S., Marjon, K. D., Banuelos, A., Khan, O., Wasserman, S. L., Spiegel, J. Y., Fernandez-Pol, S., Kuo, C. J., Sorensen, P. H., Monje, M., Majzner, R. G., Weissman, I. L., Sahaf, B., Sotillo, E., Cochran, J. R., Mackall, C. L. 2024

    Abstract

    Adoptively transferred T cells and agents designed to block the CD47-SIRPα axis are promising cancer therapeutics that activate distinct arms of the immune system1,2. Here we administered anti-CD47 antibodies in combination with adoptively transferred T cells with the goal of enhancing antitumour efficacy but observed abrogated therapeutic benefit due to rapid macrophage-mediated clearance of T cells expressing chimeric antigen receptors (CARs) or engineered T cell receptors. Anti-CD47-antibody-mediated CAR T cell clearance was potent and rapid enough to serve as an effective safety switch. To overcome this challenge, we engineered the CD47 variant CD47(Q31P) (47E), which engages SIRPα and provides a 'don't eat me' signal that is not blocked by anti-CD47 antibodies. TCR or CAR T cells expressing 47E are resistant to clearance by macrophages after treatment with anti-CD47 antibodies, and mediate substantial, sustained macrophage recruitment to the tumour microenvironment. Although many of the recruited macrophages manifested an M2-like profile3, the combined therapy synergistically enhanced antitumour efficacy. Our study identifies macrophages as major regulators of T cell persistence and illustrates the fundamental challenge of combining T-cell-directed therapeutics with those designed to activate macrophages. It delivers a therapeutic approach that is capable of simultaneously harnessing the antitumour effects of T cells and macrophages, offering enhanced potency against solid tumours.

    View details for DOI 10.1038/s41586-024-07443-8

    View details for PubMedID 38750365

    View details for PubMedCentralID 4182950

  • Prevalence and clinicopathological features of incidentally detected TRBC1-dim populations in peripheral blood flow cytometry. Leukemia & lymphoma Wadsworth, P., Zhang, J., Miller, T., Menke, J., Oak, J., Fernandez-Pol, S. 2024: 1-4

    View details for DOI 10.1080/10428194.2024.2354527

    View details for PubMedID 38747176

  • p53 immunohistochemistry as an ancillary tool for rapid assessment of residual disease in TP53-mutated acute myeloid leukemia and myelodysplastic syndromes. American journal of clinical pathology Brar, N., Lawrence, L., Fung, E., Zehnder, J. L., Greenberg, P. L., Mannis, G. N., Zhang, T. Y., Gratzinger, D., Oak, J., Silva, O., Kurzer, J., Tan, B., Menke, J. R., Fernandez-Pol, S. 2024

    Abstract

    Measurable residual disease flow cytometry (MRD-FC) and molecular studies are the most sensitive methods for detecting residual malignant populations after therapy for TP53-mutated acute myeloid leukemia and myelodysplastic neoplasms (TP53+ AML/MDS). However, their sensitivity is limited in suboptimal aspirates or when the immunophenotype of the neoplastic blasts overlaps with erythroids or normal maturing myeloid cells. In this study, we set out to determine if p53 immunohistochemistry (IHC) correlates with MRD-FC and next-generation sequencing (NGS) in the posttherapy setting and to determine the utility of p53 IHC to detect residual disease in the setting of negative or equivocal MRD-FC.We retrospectively identified 28 pre- and posttherapy bone marrow biopsy specimens from 9 patients with TP53+ AML/MDS and a p53 overexpressor phenotype by IHC (strong 3+ staining at initial diagnosis). Next-generation sequencing and/or MRD-FC results were collected for each specimen.Using a threshold of more than ten 2-3+ cells in any one 400× field, p53 IHC detected residual disease with a sensitivity of 94% and a specificity of 89%. The threshold used in this study showed a high degree of concordance among 6 blinded pathologists (Fleiss κ = 0.97).Our study suggests that p53 IHC can be used as a rapid tool (within 24 hours) to aid in the detection of residual disease that may complement MRD-FC or NGS in cases in which the flow cytometry immunophenotype is equivocal and/or the bone marrow aspirate is suboptimal.

    View details for DOI 10.1093/ajcp/aqae034

    View details for PubMedID 38643353

  • Loss of CD5-positive T-cells following anti-thymocyte globulin treatment. Journal of hematopathology Herring, M. B., Fernandez-Pol, S. 2024

    View details for DOI 10.1007/s12308-024-00581-y

    View details for PubMedID 38573562

  • The Histopathologic Features of Early COVID Pneumonia in a Pediatric Patient: New Insight into the Role of Macrophages INTERNATIONAL JOURNAL OF SURGICAL PATHOLOGY Bulterys, P. L., Xu, G., Pinsky, B. A., Troxell, M. L., Menke, J. R., Berry, G. J., Fernandez-Pol, S., Hazard, F. K. 2024
  • Clinical characteristics, treatment patterns, and outcomes of cytotoxic cutaneous T-cell lymphomas. American journal of hematology Mou, E., Fernandez-Pol, S., Li, S., Rieger, K. E., Novoa, R., Suarez, C. J., Wieland, R., Weng, W., Kim, Y. H., Khodadoust, M. S. 2024

    View details for DOI 10.1002/ajh.27266

    View details for PubMedID 38391088

  • Shared and distinct mechanisms of UBA1 inactivation across different diseases. The EMBO journal Collins, J. C., Magaziner, S. J., English, M., Hassan, B., Chen, X., Balanda, N., Anderson, M., Lam, A., Fernandez-Pol, S., Kwong, B., Greenberg, P. L., Terrier, B., Likhite, M. E., Kosmider, O., Wang, Y., Samara, N. L., Walters, K. J., Beck, D. B., Werner, A. 2024

    Abstract

    Most cellular ubiquitin signaling is initiated by UBA1, which activates and transfers ubiquitin to tens of E2 enzymes. Clonally acquired UBA1 missense mutations cause an inflammatory-hematologic overlap disease called VEXAS (vacuoles, E1, X-linked, autoinflammatory, somatic) syndrome. Despite extensive clinical investigation into this lethal disease, little is known about the underlying molecular mechanisms. Here, by dissecting VEXAS-causing UBA1 mutations, we discovered that p.Met41 mutations alter cytoplasmic isoform expression, whereas other mutations reduce catalytic activity of nuclear and cytoplasmic isoforms by diverse mechanisms, including aberrant oxyester formation. Strikingly, non-p.Met41 mutations most prominently affect transthioesterification, revealing ubiquitin transfer to cytoplasmic E2 enzymes as a shared property of pathogenesis amongst different VEXAS syndrome genotypes. A similar E2 charging bottleneck exists in some lung cancer-associated UBA1 mutations, but not in spinal muscular atrophy-causing UBA1 mutations, which instead, render UBA1 thermolabile. Collectively, our results highlight the precision of conformational changes required for faithful ubiquitin transfer, define distinct and shared mechanisms of UBA1 inactivation in diverse diseases, and suggest that specific E1-E2 modules control different aspects of tissue differentiation and maintenance.

    View details for DOI 10.1038/s44318-024-00046-z

    View details for PubMedID 38360993

  • The clinical, molecular, and prognostic features of the 2022 WHO and ICC classification systems for myelodysplastic neoplasms. Leukemia research Khanna, V., Lu, R., Kumar, J., Molina, A., Stehr, H., Spiteri, E., Spinner, M., Silva, O., Fernandez-Pol, S., Tan, B., Greenberg, P. L. 2023; 136: 107433

    Abstract

    Myelodysplastic neoplasms (MDS) are clonal disorders of bone marrow failure exhibiting a variable risk of progression to acute myeloid leukemia. MDS exhibit certain prognostic genetic or cytogenetic abnormalities, an observation that has led to both the pathologic reclassification of MDS in the 2022 World Health Organization (WHO) and International Consensus Classification (ICC) systems, as well as to an updated prognostic schema, the Molecular International Prognostic Scoring System (IPSS-M). This single-institution study characterized the molecular patterns and clinical outcomes associated with the 2022 WHO and ICC classification schemas to assess their clinical utility. Strikingly, with the exception of one individual, all 210 patients in our cohort were classified into analogous categories by the two pathologic/diagnostic schemas. Most patients (70%) were classified morphologically while the remaining 30% had genetically classified disease by both criteria. Prognostic risk, as assessed by the IPSS-M score was highest in patients with MDS with biallelic/multi-hit TP53 mutations and lowest in pts with MDS-SF3B1. Median leukemia-free survival (LFS) was shortest for those with MDS with biallelic/multi-hit TP53 (0.7 years) and longest for those with MDS with low blasts (LFS not reached). These data demonstrate the clear ability of the 2022 WHO and ICC classifications to organize MDS patients into distinct prognostic risk groups and further show that both classification systems share more similarities than differences. Incorporation of the IPSS-M and IPSS-R features provide additive prognostic and survival components to both the WHO and ICC classifications, which together enhance their utility for evaluating and treating MDS patients.

    View details for DOI 10.1016/j.leukres.2023.107433

    View details for PubMedID 38154193

  • B-lymphoblastic leukemia with transient spontaneous remission in the setting of severe group A streptococcus infection. Journal of hematopathology Gilbert, A., Tan, J., Nadimpalli, S., Orkusyan, R., Fernandez, Z. I., Oak, J., Fernandez-Pol, S. 2023; 16 (4): 223-226

    Abstract

    Spontaneous remission of B-lymphoblastic leukemia (B-ALL) in the setting of viral and bacterial infections has been reported. Here, we present a case of B-ALL that showed a complete remission in the setting of group A streptococcal bacteremia. The patient was an 11-year-old boy who presented with a sore throat, right ear pain, and rhinorrhea. Prior to the diagnosis of B-ALL, he was diagnosed with streptococcal pharyngitis and received a single dose of dexamethasone and azithromycin. One day later, he was found to be pancytopenic and an immunophenotypically abnormal B-lymphoblastic population was detected comprising 0.6% and 16.8% of the peripheral blood and bone marrow cells, respectively. Though a diagnosis of B-ALL was highly suspected, blast percentage was <20% and the bone marrow showed relatively unremarkable trilineage hematopoiesis. On close monitoring, the suspected neoplastic population became undetectable by day 17 and the patient's complete blood count (CBC) completely normalized by day 46. On day 82, a peripheral blood smear demonstrated circulating blasts. Flow cytometry of a bone marrow aspirate revealed B-lymphoblastic leukemia accounting for 94% nucleated cells, consistent with the diagnosis of B-lymphoblastic leukemia. This case is of interest as less than 20 examples of spontaneous remission of B-ALL have been reported in the literature. As the case reported here relapsed and previously reported spontaneously remitting cases have uniformly relapsed, cases of B-ALL with spontaneous remission should be followed very closely for recurrence.

    View details for DOI 10.1007/s12308-023-00564-5

    View details for PubMedID 38175433

    View details for PubMedCentralID 3309707

  • Lupus erythematosus cells in a bone marrow aspirate. Journal of hematopathology Zhang, J., Tan, B., Fernandez-Pol, S. 2023; 16 (4): 247-248

    Abstract

    A teenage girl presented with fevers of unknown origin and pancytopenia. Complete blood count showed anemia (hemoglobin, 9.0 g/dL), neutropenia (1.7 × 109/L), and thrombocytopenia (66 × 109/L). The bone marrow was hypocellular with left shifted hematopoiesis and myeloid hypoplasia. Aspirate smears were notable for a prominent population of neutrophils with crescentic nuclei that engulfed blue amorphous material (Fig. 1 panels A and B, Wright-Giemsa, magnification × 1000). The trephine biopsy showed similar cells with crescentic nuclei and eosinophilic material (Fig. 1 panels C and D, hematoxylin and eosin × 400). Flow cytometry was negative for an abnormal population. EBV by in situ hybridization and parvovirus immunohistochemistry were negative. Subsequent serologic testing was positive for ANA (1:1280), low C3/C4, anti-dsDNA, anti-SM and anti-B2GP1. A kidney biopsy demonstrated findings consistent with class III lupus nephritis.

    View details for DOI 10.1007/s12308-023-00561-8

    View details for PubMedID 38175431

  • Two cases of mycosis fungoides with large cell transformation with KMT2A rearrangements. Journal of hematopathology Wadsworth, P. A., Lawrence, L., Suarez, C. J., Saleem, A., Khodadoust, M. S., Kim, Y. H., Rieger, K. E., Fernandez-Pol, S. 2023; 16 (4): 227-234

    Abstract

    Cutaneous T-cell lymphomas (CTCL) are a clinically and molecularly heterogeneous class of lymphomas of the skin-homing T cell, and their genetic profiles are not fully characterized. Previously, rearrangements of the Lysine Methyltransferase 2A (KMT2A) gene have been identified as driver mutations only in acute leukemias. KMT2A plays a role in epigenetic regulation, and cancers with such rearrangements are responsive to epigenetic therapy including hypomethylating agents. Here, we report two cases of CTCL with novel genetic profiles. KMT2A rearrangements were identified in two aggressive cases of mycosis fungoides with large cell transformation. A KMT2A::DSCAML1 gene rearrangement was seen in Case 1, while a KMT2A::MAPRE1 fusion was identified in Case 2. These cases demonstrate that KMT2A rearrangements can be found in primary CTCLs rather than solely acute leukemias, illustrating the importance of correlating molecular findings with clinical and histologic features in diagnosis. Additionally, this finding suggests that the subset of CTCLs driven by aberrancy of the KMT2A pathway may be responsive to therapy with hypomethylating agents or menin inhibitors, as seen in acute leukemias.

    View details for DOI 10.1007/s12308-023-00567-2

    View details for PubMedID 38175436

    View details for PubMedCentralID 5854542

  • Two cases of mycosis fungoides with large cell transformation with KMT2A rearrangements JOURNAL OF HEMATOPATHOLOGY Wadsworth, P. A., Lawrence, L., Suarez, C. J., Saleem, A., Khodadoust, M. S., Kim, Y. H., Rieger, K. E., Fernandez-Pol, S. 2023
  • B-lymphoblastic leukemia with transient spontaneous remission in the setting of severe group A streptococcus infection JOURNAL OF HEMATOPATHOLOGY Gilbert, A., Tan, J., Nadimpalli, S., Orkusyan, R., Fernandez, Z., Oak, J., Fernandez-Pol, S. 2023
  • Shared and Distinct Mechanisms of UBA1 Inactivation Across Different Diseases. bioRxiv : the preprint server for biology Collins, J. C., Magaziner, S. J., English, M., Hassan, B., Chen, X., Balanda, N., Anderson, M., Lam, A., Fernandez-Pol, S., Kwong, B., Greenberg, P. L., Terrier, B., Likhite, M. E., Kosmider, O., Wang, Y., Samara, N. L., Walters, K. J., Beck, D. B., Werner, A. 2023

    Abstract

    Most cellular ubiquitin signaling is initiated by UBA1, which activates and transfers ubiquitin to tens of E2 enzymes. Clonally acquired UBA1 missense mutations cause an inflammatory-hematologic overlap disease called VEXAS (vacuoles, E1, X-linked, autoinflammatory, somatic) syndrome. Despite extensive clinical investigation into this lethal disease, little is known about the underlying molecular mechanisms. Here, by dissecting VEXAS-causing UBA1 mutations, we discovered that p.Met41 mutations alter cytoplasmic isoform expression, whereas other mutations reduce catalytic activity of nuclear and cytoplasmic isoforms by diverse mechanisms, including aberrant oxyester formation. Strikingly, non-p.Met41 mutations most prominently affect transthioesterification, revealing ubiquitin transfer to cytoplasmic E2 enzymes as a shared property of pathogenesis amongst different VEXAS syndrome genotypes. A similar E2 charging bottleneck exists in some lung cancer-associated UBA1 mutations, but not in spinal muscular atrophy-causing UBA1 mutations, which instead, render UBA1 thermolabile. Collectively, our results highlight the precision of conformational changes required for faithful ubiquitin transfer, define distinct and shared mechanisms of UBA1 inactivation in diverse diseases, and suggest that specific E1-E2 modules control different aspects of tissue differentiation and maintenance.

    View details for DOI 10.1101/2023.10.10.561769

    View details for PubMedID 37873213

    View details for PubMedCentralID PMC10592724

  • Lupus erythematosus cells in a bone marrow aspirate JOURNAL OF HEMATOPATHOLOGY Zhang, J., Tan, B., Fernandez-Pol, S. 2023
  • Genomic abnormalities involving class I HLA are common in advanced cutaneous T-cell lymphoma Kwang, A., Duran, G., Fernandez-Pol, S., Li, S., Najidh, S., Torres, A., Herrera, M., Wang, E., Kurtz, D., Kim, Y. H., Khodadoust, M. ELSEVIER SCI LTD. 2023: S14
  • SATB2 expression in hematolymphoid neoplasms. Journal of hematopathology Tiu, G. C., Natkunam, Y., Fernandez-Pol, S. 2023; 16 (2): 119-122

    View details for DOI 10.1007/s12308-023-00543-w

    View details for PubMedID 38175442

    View details for PubMedCentralID 6320370

  • SATB2 expression in hematolymphoid neoplasms JOURNAL OF HEMATOPATHOLOGY Tiu, G. C., Natkunam, Y., Fernandez-Pol, S. 2023
  • Clinicopathologic characteristics, genetic features, and treatment options for acute lymphoblastic leukemia with JAK2 rearrangement-A 10-case study and literature review. Human pathology Zhang, L., Shah, B., Zhang, Y., Tashkandi, H., Xiao, W., Fernandez-Pol, S., Vergara-Lluri, M., Hussaini, M., Song, J., Lancet, J., Moscinski, L., Yun, S., Lu, C. M., Medeiros, L. J., Tang, G. 2023

    Abstract

    JAK2 rearrangement (JAK2-R) in acute lymphoblastic leukemia (ALL) is rare and often categorized as B-ALL with BCR::ABL1-like features based on the World Health Organization classification. We report 10 patients with JAK2-R ALL, 9 males and 1 female, with a median age 40.5 years. Eight patients presented with marked leukocytosis (median WBC, 63 × 10 9/L) and hypercellular (>95%) bone marrow with increased lymphoblasts (72%-95%). There was no evidence of bone marrow fibrosis or hypereosinophilia. Immunophenotypic analysis showed 9 B-cell and 1 T-cell neoplasms. Using fluorescence in situ hybridization (FISH) and RNA sequencing analysis, JAK2 partners were identified for 7 cases and included PCM1 (n=4), ETV6 (n=2) and BCR (n=1). All patients received upfront polychemotherapy. Additionally, 2 patients received ruxolitinib, 2 received allogeneic stem cell transplant, and 1 received CAR-T therapy. The 1- and 3-year overall survival rates were 55.6% and 22.2%, respectively. A literature review identified 24 B-ALL and 4 T-ALL cases with JAK2-R reported, including 16 males, 6 females and 6 gender not stated. Many JAK2 partner-genes were reported with the most common being PAX5 (n=7), ETV6 (n=4), BCR (n=3) and PCM1 (n=2). Survival data or 13 reported cases showed 1- and 3-year overall survival rates of 41.7% and 41.7%, respectively. In summary, JAK2-R ALL occurs more often in adult males, are mostly of B-cell lineage, and associated with an aggressive clinical course. Absence of eosinophilia and bone marrow fibrosis and no evidence of preexisting/concurrent JAK2-R myeloid neoplasms distinguish JAK2-R ALL from other myeloid/lymphoid neoplasms with eosinophilia and JAK2-R.

    View details for DOI 10.1016/j.humpath.2023.03.002

    View details for PubMedID 36958463

  • Molecular profiling identifies at least 3 distinct types of post-transplant lymphoproliferative disorder involving CNS. Blood advances Guney, E., Lucas, C. G., Singh, K., Pekmezci, M., Fernandez-Pol, S., Mirchia, K., Toland, A., Vogel, H., Bannykh, S. I., Schafernak, K. T., Alexandrescu, S., Mobley, B. C., Powell, S. Z., Davidson, C., Neltner, J., Boue, D. R., Hattab, E. M., Ferris, S. P., Ohgami, R. S., Rubenstein, J. L., Bollen, A. W., Tihan, T., Perry, A., Solomon, D. A., Wen, K. W. 2023

    View details for DOI 10.1182/bloodadvances.2022009521

    View details for PubMedID 36897259

  • Comparison of two immunohistochemical staining protocols for ALK demonstrates non-inferiority of a 5A4 clone-based protocol versus an ALK01 clone-based protocol for the diagnosis of ALK + anaplastic large cell lymphoma. Journal of hematopathology Fernandez-Pol, S., Ferreira, C. R., Manohar, V., Sanches, J. A., Lage, L. A., Pereira, J., Zerbini, M. C., Gratzinger, D., Natkunam, Y. 2023; 16 (1): 1-5

    Abstract

    Detection of ALK rearrangement and/or expression of the ALK protein is an essential component in the evaluation of many neoplasms. Variability has been reported in the ability of different antibody clones to detect ALK expression. The ALK01 clone is commonly used to detect ALK expression in ALK-positive anaplastic large cell lymphoma (ALK + ALCL). However, this clone has been shown to lack sensitivity when used for solid tumors. The aim of this study was to determine if our high-sensitivity 5A4-based immunohistochemistry protocol is non-inferior to our ALK01-based protocol for the detection of ALK expression in ALK + ALCL. To compare the two protocols, we stained tissue microarrays of 126 hematolymphoid neoplasms and an additional 21 primary cutaneous ALK-negative anaplastic large cell lymphomas with both protocols. All 28 ALK + ALCL samples that were positive for the ALK01 antibody were also positive for the 5A4 clone. Three cases on the tissue microarray that were negative with the ALK01 antibody were clearly positive with the 5A4 antibody. We subsequently stained whole tissue sections of these three cases with the ALK01 antibody and found that these three cases were indeed positive with the ALK01 protocol, suggesting that the absence of staining on the tissue microarray samples was due to a combination of sampling error as well as a dimmer signal with the ALK01 protocol. Our study demonstrates that our 5A4-based protocol is non-inferior to the ALK01 antibody for the diagnosis of ALK-positive anaplastic large cell lymphoma, thus allowing our laboratory to discontinue the use of the ALK01-based protocol.

    View details for DOI 10.1007/s12308-023-00531-0

    View details for PubMedID 38175372

  • Isolated Sixth Nerve Palsies in a Child With Familial Hemophagocytic Lymphohistiocytosis Type 2. Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society Chiang, H. H., Fernandez-Pol, S., Bae, G. H., Rieger, K. E., Dahmoush, H. M., Beres, S. J. 2023; 43 (1): 137-140

    Abstract

    A previously healthy 2-year-old boy presented with a left sixth cranial nerve palsy. There was a family history of multiple sclerosis and optic neuritis. Neuroimaging showed multiple foci of T2/FLAIR hyperintense signal abnormality in both cerebral hemispheres and in the brainstem. The initial diagnosis was suspicious for demyelinating disease. However, there was no clinical improvement after a course of corticosteroids, and there was no change in his follow-up MRI. He later developed bilateral sixth nerve palsies, with esotropia addressed with bilateral medial rectus botulinum toxin injections. A brain biopsy was planned. However, his 3-month-old sister was separately admitted for fever and pancytopenia. She had markedly elevated ferritin, D-dimer, triglycerides, sIL-2R, CXCL9, and IL-18 and low fibrinogen. Her bone marrow biopsy showed hemophagocytosis. Genetic testing of both siblings revealed biallelic mutations in the PRF1 locus. The final diagnosis of familial hemophagocytic lymphohistiocytosis Type 2 was made. Both siblings underwent chemotherapy. The boy's sixth nerve palsies and MRI abnormalities resolved. Both siblings then went on to undergo bone marrow transplant.

    View details for DOI 10.1097/WNO.0000000000001807

    View details for PubMedID 36790062

  • TRBC1 enables identification of an otherwise immunophenotypically silent case of angioimmunoblastic T-cell lymphoma. Journal of hematopathology Zhang, J., Fernandez-Pol, S. 2023; 16 (1): 59-61

    View details for DOI 10.1007/s12308-023-00533-y

    View details for PubMedID 38175375

    View details for PubMedCentralID 5142610

  • TRBC1 enables identification of an otherwise immunophenotypically silent case of angioimmunoblastic T-cell lymphoma JOURNAL OF HEMATOPATHOLOGY Zhang, J., Fernandez-Pol, S. 2023
  • Comparison of two immunohistochemical staining protocols for ALK demonstrates non-inferiority of a 5A4 clone-based protocol versus an ALK01 clone-based protocol for the diagnosis of ALK plus anaplastic large cell lymphoma JOURNAL OF HEMATOPATHOLOGY Fernandez-Pol, S., Ferreira, C. R., Manohar, V., Sanches, J., Lage, L. C., Pereira, J., Zerbini, M. N., Gratzinger, D., Natkunam, Y. 2023
  • Clinical Characteristics, Treatment Patterns, and Outcomes of Cytotoxic Cutaneous T-Cell Lymphomas Mou, E., Fernandez-Pol, S., Li, S., Kim, Y. H., Khodadoust, M. S. AMER SOC HEMATOLOGY. 2022: 6552-6553
  • Characterization of Clinical, Molecular, and Prognostic Features of the WHO 2022 Classification System for Myelodysplastic Neoplasms (MDS) Khanna, V., Lu, R., Kumar, J., Stehr, H., Spinner, M. A., Silva, O., Fernandez-Pol, S., Oak, J. S., Tan, B., Greenberg, P. L. AMER SOC HEMATOLOGY. 2022: 6955-6957
  • Correlation of Mutational Profiles and Cytogenetics with Morphologic Dysplasia in Myelodysplastic Syndromes Kumar, J., Khanna, V., Lu, R., Stehr, H., Spinner, M. A., Silva, O., Fernandez-Pol, S., Oak, J. S., Greenberg, P. L., Tan, B. AMER SOC HEMATOLOGY. 2022: 4053-4055
  • Digital Image Analysis and Quantitative Bead Standards in Root Cause Analysis of Immunohistochemical Staining Variability: A Real-world Example. Applied immunohistochemistry & molecular morphology : AIMM Rojansky, R., Sompuram, S. R., Gomulia, E., Natkunam, Y., Troxell, M. L., Fernandez-Pol, S. 2022

    Abstract

    Assessment of automated immunohistochemical staining platform performance is largely limited to the visual evaluation of individual slides by trained personnel. Quantitative assessment of stain intensity is not typically performed. Here we describe our experience with 2 quantitative strategies that were instrumental in root cause investigations performed to identify the sources of suboptimal staining quality (decreased stain intensity and increased variability). In addition, these tools were utilized as adjuncts in validation of a new immunohistochemical staining instrument. The novel methods utilized in the investigation include quantitative assessment of whole slide images (WSI) and commercially available quantitative calibrators. Over the course of ~13 months, these methods helped to identify and verify correction of 2 sources of suboptimal staining. One root cause of suboptimal staining was insufficient/variable power delivery from our building's electrical circuit. This led us to use uninterruptible power managers for all automated immunostainer instruments, which restored expected stain intensity and consistency. Later, we encountered one instrument that, despite passing all vendor quality control checks and not showing error alerts was suspected of yielding suboptimal stain quality. WSI analysis and quantitative calibrators provided a clear evidence that proved critical in confirming the pathologists' visual impressions. This led to the replacement of the instrument, which was then validated using a combination of standard validation metrics supplemented by WSI analysis and quantitative calibrators. These root cause analyses document 2 variables that are critical in producing optimal immunohistochemical stain results and also provide real-world examples of how the application of quantitative tools to measure automated immunohistochemical stain output can provide a greater objectivity when assessing immunohistochemical stain quality.

    View details for DOI 10.1097/PAI.0000000000001045

    View details for PubMedID 35876743

  • Resistance to mogamulizumab is associated with loss of CCR4 in Cutaneous T-cell Lymphoma. Blood Beygi, S., Duran, G. E., Fernandez-Pol, S., Rook, A. H., Kim, Y. H., Khodadoust, M. S. 2022

    Abstract

    Mogamulizumab is a humanized anti-CCR4 antibody approved for the treatment of mycosis fungoides and Sezary Syndrome. Despite almost universal expression of CCR4 in these diseases, most patients eventually develop resistance to mogamulizumab. We tested whether resistance to mogamulizumab is associated with loss of CCR4 expression. We identified 17 patients with mycosis fungoides or Sezary syndrome who either were intrinsically resistant or acquired resistance to mogamulizumab. Low expression of CCR4 by immunohistochemistry or flow cytometry was found in 65% of patients. Novel emergent CCR4 mutations targeting the N-terminal and transmembrane domains were found in 3 patients after disease progression. Emerging CCR4 copy number loss was detected in 2 patients with CCR4 mutations. Acquisition of CCR4 genomic alterations corresponded with loss of CCR4 antigen expression. We also report on outcomes of three cutaneous T-cell lymphoma patients with gain-of-function CCR4 mutations treated with mogamulizumab. Our study indicates that resistance to mogamulizumab in CTCL frequently involves loss of CCR4 expression and emergence of CCR4 genomic alterations. This finding has implications for management and monitoring of CTCL patients on mogamulizumab and development of future CCR4-directed therapies.

    View details for DOI 10.1182/blood.2021014468

    View details for PubMedID 35436328

  • Identification of "ER Low Positive" Breast Cancers Is Associated with Immunohistochemical Assay Conditions in CAP Proficiency Testing PM2 Survey Bean, G., Souers, R., Fernandez-Pol, S., Bellizzi, A. SPRINGERNATURE. 2022: 94-95
  • Identification of "ER Low Positive" Breast Cancers Is Associated with Immunohistochemical Assay Conditions in CAP Proficiency Testing PM2 Survey Bean, G., Souers, R., Fernandez-Pol, S., Bellizzi, A. SPRINGERNATURE. 2022: 94-95
  • Molecular Characterization of Chronic Lymphocytic Leukemia with Progression to Classic Hodgkin Lymphoma Tiu, G., Xu, G., Gratzinger, D., Fernandez-Pol, S. SPRINGERNATURE. 2022: 1029-1030
  • Expression of CD47 Protein in Hematolymphoid Neoplasms: Implications for CD47-Mediated Cancer Immunotherapy Zhang, J., Bulterys, P., Fernandez-Pol, S., Younes, S., Zhao, S., Mansoor, A., Natkunam, Y. SPRINGERNATURE. 2022: 1052-1053
  • Molecular Characterization of Chronic Lymphocytic Leukemia with Progression to Classic Hodgkin Lymphoma Tiu, G., Xu, G., Gratzinger, D., Fernandez-Pol, S. SPRINGERNATURE. 2022: 1029-1030
  • Expression of CD47 Protein in Hematolymphoid Neoplasms: Implications for CD47-Mediated Cancer Immunotherapy Zhang, J., Bulterys, P., Fernandez-Pol, S., Younes, S., Zhao, S., Mansoor, A., Natkunam, Y. SPRINGERNATURE. 2022: 1052-1053
  • Selective Targeting of Immune Modulatory Proteins to Mitigate Fibrosis and Inflammation in Sclerodermatous Graft-Vs-Host Disease Cui, L., De Souza, C., Lerbs, T., Poyser, J., Kooshesh, M., Saleem, A., Rieger, K., Brown, B., Kwong, B., Fernandez-Pol, S., Arai, S., Shizuru, J. A., Mueller, A. S., Wernig, G. AMER SOC HEMATOLOGY. 2021
  • Two Cases of Mycosis Fungoides With PCM1-JAK2 Fusion. JCO precision oncology Fernandez-Pol, S., Neishaboori, N., Chapman, C. M., Khodadoust, M. S., Kim, Y. H., Rieger, K. E., Suarez, C. J. 2021; 5: 646-652

    View details for DOI 10.1200/PO.20.00366

    View details for PubMedID 34994608

  • Mechanisms of resistance to anti-CCR4 antibody, mogamulizumab, in cutaneous T cell lymphoma Beygi, S., Fernandez-Pol, S., Duran, G., Wang, E. B., Kim, Y., Khodadoust, M. ELSEVIER SCI LTD. 2021: S8
  • Angioimmunoblastic T-cell lymphoma diagnosed from pleural fluid by integration of morphologic, immunophenotypic, and molecular findings. Diagnostic cytopathology Tan, B., Martin, B., Fernandez-Pol, S. 2021

    Abstract

    An 88-year-old man with end-stage renal disease on hemodialysis presented with shortness of breath and was found to have lower extremity edema and bilateral pleural effusions on a chest X-ray. A therapeutic and diagnostic thoracentesis was performed, and cytologic examination revealed atypical mononuclear cells. Based on this, flow cytometry was performed on the pleural fluid, along with immunostains on the cellblock and a next-generation sequencing (NGS) panel. A definitive diagnosis of angioimmunoblastic T-cell lymphoma (AITL) was made based on demonstrating an atypical T follicular helper cell population expressing CD10, BCL6, CXCL13, CD200, CD57, and PD1, and detection of pathogenic variants in RHOA, IDH2, and TET2. This case represents the first reported case where a primary diagnosis of AITL was made on a body fluid specimen and highlights how immunophenotyping and NGS can provide a definitive diagnosis of AITL on a cytologic specimen.

    View details for DOI 10.1002/dc.24861

    View details for PubMedID 34449978

  • DLBCL-Morph: Morphological features computed using deep learning for an annotated digital DLBCL image set. Scientific data Vrabac, D., Smit, A., Rojansky, R., Natkunam, Y., Advani, R. H., Ng, A. Y., Fernandez-Pol, S., Rajpurkar, P. 2021; 8 (1): 135

    Abstract

    Diffuse Large B-Cell Lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. Though histologically DLBCL shows varying morphologies, no morphologic features have been consistently demonstrated to correlate with prognosis. We present a morphologic analysis of histology sections from 209 DLBCL cases with associated clinical and cytogenetic data. Duplicate tissue core sections were arranged in tissue microarrays (TMAs), and replicate sections were stained with H&E and immunohistochemical stains for CD10, BCL6, MUM1, BCL2, and MYC. The TMAs are accompanied by pathologist-annotated regions-of-interest (ROIs) that identify areas of tissue representative of DLBCL. We used a deep learning model to segment all tumor nuclei in the ROIs, and computed several geometric features for each segmented nucleus. We fit a Cox proportional hazards model to demonstrate the utility of these geometric features in predicting survival outcome, and found that it achieved a C-index (95% CI) of 0.635 (0.574,0.691). Our finding suggests that geometric features computed from tumor nuclei are of prognostic importance, and should be validated in prospective studies.

    View details for DOI 10.1038/s41597-021-00915-w

    View details for PubMedID 34017010

  • Radiation Therapy for Primary Cutaneous Gamma Delta Lymphoma Prior to Stem Cell Transplantation. Cancer investigation Wu, Y. F., Skinner, L., Lewis, J., Khodadoust, M. S., Kim, Y. H., Kwong, B. Y., Weng, W., Hoppe, R. T., Sodji, Q., Hui, C., Kastelowitz, N., Fernandez-Pol, S., Hiniker, S. M. 2021: 1–11

    Abstract

    We present a patient with widespread PCGD-TCL of the bilateral arms and legs, who underwent radiotherapy with 34Gy in 17 fractions using circumferential VMAT and 3-D printed bolus to the 4 extremities prior to planned stem cell transplant, who was then found to have progression in the liver, lung, and skin, followed by drastic regression of all in and out-of-field lesions on imaging 1.5months later. The cause of regression may be related to a radiation-induced abscopal effect from the immunomodulatory effects of radiation, or related to immune reactivation in the setting of cessation of systemic immunosuppressive agents.

    View details for DOI 10.1080/07357907.2021.1919696

    View details for PubMedID 33899635

  • Two Cases of Mycosis Fungoides With PCM1-JAK2 Fusion JCO PRECISION ONCOLOGY Fernandez-Pol, S., Neishaboori, N., Chapman, C. M., Khodadoust, M. S., Kim, Y. H., Rieger, K. E., Suarez, C. J. 2021; 5: 646-652
  • A Method for Assessing Performance of Automated Immunohistochemical Staining Platforms Using Digital Image Analysis Rojansky, R., Fernandez-Pol, S., Gomulia, E., Natkunam, Y., Troxell, M. SPRINGERNATURE. 2021: 1172–73
  • Pembrolizumab in mycosis fungoides with PD-L1 structural variants. Blood advances Beygi, S. n., Fernandez-Pol, S. n., Duran, G. n., Wang, E. B., Stehr, H. n., Zehnder, J. L., Ramchurren, N. n., Fling, S. P., Cheever, M. A., Weng, W. K., Kim, Y. H., Khodadoust, M. S. 2021; 5 (3): 771–74

    View details for DOI 10.1182/bloodadvances.2020002371

    View details for PubMedID 33560388

  • GloFlow: Whole Slide Image Stitching from Video Using Optical Flow and Global Image Alignment Krishna, V., Joshi, A., Vrabac, D., Bulterys, P., Yang, E., Fernandez-Pol, S., Ng, A. Y., Rajpurkar, P., DeBruijne, M., Cattin, P. C., Cotin, S., Padoy, N., Speidel, S., Zheng, Y., Essert, C. SPRINGER INTERNATIONAL PUBLISHING AG. 2021: 519-528
  • A novel activating JAK1 mutation in chronic eosinophilic leukemia. Blood advances Shomali, W., Damnernsawad, A., Theparee, T., Sampson, D., Morrow, Q., Yang, F., Fernandez-Pol, S., Press, R. D., Zehnder, J. L., Tyner, J. W., Gotlib, J. R. 2021

    Abstract

    Hypereosinophilia (HE) has been arbitrarily defined as persistent eosinophilia >1.5 x109/L, and is broadly divided into primary (clonal or neoplastic; HEN), secondary/reactive (HER), or of undetermined significance (HEUS) when no cause is identified. The use of myeloid next generation sequencing panels has led to the detection of several mutations in patients previously diagnosed with HEUS, reassigning some patients to the category of HEN, specifically the World Health Organization category of chronic eosinophilic leukemia, not otherwise specified (CEL, NOS). Here we describe a novel somatic JAK1 pseudokinase domain mutation (R629_S632delinsSA) in a patient with HE that had been initially characterized as a variant of uncertain significance. We performed functional studies that demonstrate that this mutation results in growth factor independence of Ba/F3 cells in vitro and activation of the Janus Kinase-Signal Transducer and Activator of Transcription Proteins (JAK-STAT) pathway. These effects were abrogated by the JAK1/JAK2 inhibitor ruxolitinib. The R629_S632delinsSA is the first known somatic mutation in JAK1 linked to a clonal eosinophilic neoplasm, and highlights the importance of the JAK-STAT pathway in eosinophil survival.

    View details for DOI 10.1182/bloodadvances.2021004237

    View details for PubMedID 34496019

  • Epstein-Barr virus-positive lymphoproliferative disorder manifesting as pulmonary disease in a patient with acute myeloid leukemia: a case report. Journal of medical case reports Dutta, R. n., Miao, S. Y., Phan, P. n., Fernandez-Pol, S. n., Shiraz, P. n., Ho, D. n., Mannis, G. N., Zhang, T. Y. 2021; 15 (1): 170

    Abstract

     Patients with lymphoproliferative disorders following hematopoietic stem cell transplant (HSCT) most commonly present with fever and lymphadenopathy within the first 5 months of transplant. Pulmonary post-transplant lymphoproliferative disorder (PTLD) is a particularly aggressive and rapidly progressive disease, with high morbidity and mortality. There are a very limited number of reported pulmonary PTLD cases following HSCT in patients with acute myeloid leukemia (AML). Early diagnosis and detection of pulmonary PTLD is critical given its high lethality. However, variable clinical presentations and nonspecific radiographic findings make pulmonary PTLD difficult to distinguish from other more common causes of pulmonary disease in AML patients.Here, we describe a 68-year-old Caucasian man who presented for salvage induction therapy following relapse of his AML after a haploidentical allogeneic HSCT 10 months earlier. He developed recurrent fevers, dry cough, and hypoxemia, with chest computed tomography (CT) showing bibasilar consolidations and increased nodularity without increased lymphadenopathy. His symptoms initially improved with antibiotic and antifungal therapy, but his follow-up chest CT showed progression of disease despite symptomatic improvement. Epstein-Barr virus (EBV) was detected in his blood by polymerase chain reaction (PCR), and a lung biopsy revealed monomorphic PTLD with B cells positive for EBV. Unfortunately, the patient's condition rapidly deteriorated, and he passed away prior to treatment initiation. To our knowledge, this is the first reported case of an AML patient developing pulmonary PTLD relatively late in his post-transplant course in the setting of relapsed disease and salvage therapy. Pulmonary PTLD, a rare but highly lethal disorder, can imitate the symptoms and radiographic findings of pneumonia, a common diagnosis in immunocompromised AML patients. This case illustrates the importance of considering pulmonary PTLD in the differential diagnosis for pulmonary disease in AML patients with a history of HSCT, especially in the setting of progressive radiographic findings despite broad antibacterial and antifungal therapy. Further, our case demonstrates the importance of biopsy and uninterrupted EBV DNA monitoring in the definitive diagnosis of PTLD, given nonspecific symptomatology and radiographic findings.

    View details for DOI 10.1186/s13256-021-02744-2

    View details for PubMedID 33773605

  • Jun Activation in Dermal Fibroblasts Promotes Fibrosis and Inflammation in Sclerodermatous Graft-vs-host Disease in Mice and Humans Mueller, A., Cui, L., Lerbs, T., King, M., Muscat, C., Shibata, T., Lee, J., Brown, R., Fernandez-Pol, S., Arai, S., Shizuru, J., Wernig, G. SPRINGERNATURE. 2020: 13–14
  • Two Cases With Features of Lymphocyte Variant Hypereosinophilic Syndrome With STAT3 SH2 Domain Mutations. The American journal of surgical pathology Fernandez-Pol, S., Petersen, B., Murphy, J., Oak, J. S., Wang, E. B., Rieger, K. E., Kim, Y. H., Khodadoust, M. S., Suarez, C. J. 2020

    Abstract

    Lymphocyte variant hypereosinophilic syndrome (LV-HES) is a rare cause of eosinophilia that is due to eosinophilipoietic cytokine production by an immunophenotypically abnormal T-cell clone. The molecular pathogenesis of this disorder is largely unknown and only 1 case of LV-HES with a pathogenic STAT3 mutation has been described thus far. Here we report 2 cases of LV-HES with STAT3 SH2 domain mutations. These cases further support the model that activation of STAT3 signaling through STAT3 SH2 domain mutations is a recurrent event in LV-HES.

    View details for DOI 10.1097/PAS.0000000000001604

    View details for PubMedID 33060403

  • Cutaneous T-cell lymphomas with pathogenic somatic mutations and absence of detectable clonal T-cell receptor gene rearrangement: two case reports. Diagnostic pathology Rojansky, R., Fernandez-Pol, S., Wang, E., Rieger, K. E., Novoa, R. A., Zehnder, J. L., Kunder, C. A., Kim, Y. H., Khodadoust, M. S., Brown, R. A. 2020; 15 (1): 122

    Abstract

    BACKGROUND: Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of extranodal non-Hodgkin lymphomas for which diagnosis can be challenging given the potential for overlap with inflammatory dermatoses. Current diagnostic criteria for CTCL incorporate clinical and histopathologic findings as well as results of T-cell receptor (TCR) gene sequencing. Molecular interrogation of TCR genes, TRG and TRB, has provento be a critical tool for confirming diagnoses of CTCL and for disease tracking after initiation of therapy or after stem cell transplant. Methods for confirming a diagnosis of lymphoma in the absence of TCR gene clonality are lacking. We present two patients with CTCL with pathogenic somatic mutations in the absence of TRG and TRB clonality.CASE PRESENTATIONS: Case 1: A 38-year-old male had a 19-year history of a diffuse skin rash with papulosquamous, granulomatous, and verrucous features and progressive ulcerated plaques and tumors demonstrating an atypical CD4+ T-cell infiltrate with expression of cytotoxic markers CD56, TIA-1, granzyme, and perforin on histopathology. No definitive evidence for T-cell clonality was detected by conventional PCR of 6 biopsies or by next-generation sequencing (NGS) of 14 biopsies. Somatic mutational profiling of a skin biopsy revealed pathogenic mutations in PIKC3D and TERT promoter hotspots, confirming the presence of a clonal process. Case 2: A 69-year-old male with a 13-year history of progressive, diffuse hypertrophic and eroded plaques showed an atypical CD4+ T-cell infiltrate with subset expression of TIA-1 and granzyme on histopathology. No TCR clonality was detected by TCR-NGS of 6 biopsies. Somatic mutational profiling of a skin biopsy detected a pathogenic mutation in TP53, confirming the presence of a clonal process.CONCLUSIONS: These cases highlight how detection of pathogenic somatic mutations can confirma diagnosis of lymphoma in a clinically and histopathologically suspicious cutaneous lymphoid proliferation without detectable TCR clonality.

    View details for DOI 10.1186/s13000-020-01022-x

    View details for PubMedID 32988392

  • Differentiation syndrome during ivosidenib treatment with immunohistochemistry showing isocitrate dehydrogenase R132H mutation. Journal of cutaneous pathology Tabata, M. M., Chase, M., Kwong, B. Y., Novoa, R. A., Fernandez-Pol, S. 2020

    Abstract

    We report a case of differentiation syndrome in a patient receiving the IDH1 inhibitor ivosidenib, with skin biopsy showing isocitrate dehydrogenase (IDH) R132H-mutated leukemia cutis. A 72-year-old man with IDH1-mutated acute myeloid leukemia (AML), status-post allogeneic cell transplantation, on ivosidenib for six months, was admitted for culture-negative neutropenic fever, pink and purpuric plaques and patches on the legs, abdomen and back, edema, hypotension, and shortness of breath. Skin biopsy revealed an infiltrate of atypical, immature, myeloperoxidase-positive mononuclear cells compatible with leukemia cutis or Sweet syndrome. Although dermal edema and interstitial neutrophilic infiltrate with karyorrhexis characteristic of Sweet syndrome were not seen, the atypical cells lacked expression of CD117 and CD34, which were expressed in the original leukemia. Additional immunohistochemical staining of suspected blasts was strongly positive for IDH1 R132H, suggesting a diagnosis of leukemia cutis. As the immunophenotype of blasts in skin infiltrates can significantly differ from the immunophenotype seen in blood and bone marrow, this case demonstrates that mutation-specific antibodies such as anti-IDH1 R132H may be useful to help distinguish malignant from non-malignant infiltrates in the skin. Furthermore, differentiation syndrome may demonstrate histologic features of leukemia cutis on skin biopsy. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/cup.13780

    View details for PubMedID 32588467

  • A Case of G6PC3 Congenital Neutropenia, Misdiagnosed As Evans Syndrome Camacho, J., Brar, R., Chapman, C., Fernandez-Pol, S., Weinacht, K., Gernez, Y. SPRINGER/PLENUM PUBLISHERS. 2020: S131–S132
  • Cutaneous Pleomorphic Fibromas Arising in Patients with Germline TP53 Mutations. Journal of cutaneous pathology Cloutier, J. M., Shalin, S. C., Lindberg, M., Gardner, J. M., Fernandez-Pol, S., Zaba, L., Novoa, R., Brown, R. A. 2020

    Abstract

    Pleomorphic fibromas are rare benign cutaneous neoplasms associated with deletion/loss of chromosomes 13q and 17p, where RB1 and TP53 are located, respectively. Herein, we report five cases of pleomorphic fibroma arising in patients with germline TP53 mutations, suggesting a potential link with Li-Fraumeni syndrome. All three patients were female and young (mean age 27) with a strong personal and/or family oncologic history and confirmed pathogenic germline TP53 mutations. In two patients, multiple pleomorphic fibromas were diagnosed. Clinically, the lesions arose at various cutaneous sites and were small (≤2cm) and raised (4/5). Histologically, the tumors were paucicellular, comprised of atypical spindled to stellate cells with hyperchromatic and variably pleomorphic nuclei. Mitotic activity was exceedingly low, although rare atypical mitotic figures were seen in one case. Immunohistochemically, the tumor cells were diffusely positive for p16 (3/3) and showed loss of Rb expression (5/5). All cases showed aberrant p53 expression (overexpression in 4, complete loss in 1). The tumors have followed a benign clinical course with no evidence of progression or recurrence. In conclusion, the development of multiple pleomorphic fibromas in a young patient may be a clue to an underlying genetic cancer syndrome involving TP53. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/cup.13686

    View details for PubMedID 32187703

  • Erythema of the skin after breast radiotherapy: It is not always recurrence. International wound journal Gutkin, P. M., Fernandez-Pol, S. n., Horst, K. C. 2020

    Abstract

    Recurrence of breast cancer is a predominant fear for patients who were treated for breast cancer. Acute and late dermatologic effects of radiotherapy are not uncommon and could have similar characteristics to breast cancer recurrence. Thus, it is important to highlight key differences between the clinical and histologic presentations of radiation effects and recurrence. Herein, we present two patients who presented with late dermatologic effects of radiotherapy months to years after treatment, neither of whom had workup consistent with cancer recurrence. We provide clinical and microscopic descriptions of each case and provide a review to differentiate various dermatologic conditions. This report aims to outline potential late dermatologic effects of radiation treatment and emphasise that changes in the breast do not always signal breast cancer recurrence.

    View details for DOI 10.1111/iwj.13350

    View details for PubMedID 32227450

  • Reticulohistiocytoma (solitary epithelioid histiocytoma) with mutations in RAF1 and TSC2. Journal of cutaneous pathology Bahrani, E. n., Fernandez-Pol, S. n., Wang, J. Y., Aasi, S. Z., Brown, R. A., Novoa, R. A. 2020

    View details for DOI 10.1111/cup.13727

    View details for PubMedID 32342514

  • Multiplexed single-cell morphometry for hematopathology diagnostics. Nature medicine Tsai, A. G., Glass, D. R., Juntilla, M. n., Hartmann, F. J., Oak, J. S., Fernandez-Pol, S. n., Ohgami, R. S., Bendall, S. C. 2020; 26 (3): 408–17

    Abstract

    The diagnosis of lymphomas and leukemias requires hematopathologists to integrate microscopically visible cellular morphology with antibody-identified cell surface molecule expression. To merge these into one high-throughput, highly multiplexed, single-cell assay, we quantify cell morphological features by their underlying, antibody-measurable molecular components, which empowers mass cytometers to 'see' like pathologists. When applied to 71 diverse clinical samples, single-cell morphometric profiling reveals robust and distinct patterns of 'morphometric' markers for each major cell type. Individually, lamin B1 highlights acute leukemias, lamin A/C helps distinguish normal from neoplastic mature T cells, and VAMP-7 recapitulates light-cytometric side scatter. Combined with machine learning, morphometric markers form intuitive visualizations of normal and neoplastic cellular distribution and differentiation. When recalibrated for myelomonocytic blast enumeration, this approach is superior to flow cytometry and comparable to expert microscopy, bypassing years of specialized training. The contextualization of traditional surface markers on independent morphometric frameworks permits more sensitive and automated diagnosis of complex hematopoietic diseases.

    View details for DOI 10.1038/s41591-020-0783-x

    View details for PubMedID 32161403

  • A Survey of Somatic Mutations in 41 Genes in a Cohort of T-Cell Lymphomas Identifies Frequent Mutations in Genes Involved in Epigenetic Modification APPLIED IMMUNOHISTOCHEMISTRY & MOLECULAR MORPHOLOGY Fernandez-Pol, S., Ma, L., Joshi, R. P., Arber, D. A. 2019; 27 (6): 416–22
  • Additional considerations related to the elusive boundaries of EBV-associated T/NK-cell lymphoproliferative disorders. Haematologica Fernandez-Pol, S., Silva, O., Natkunam, Y. 2019; 104 (3): e125–e126

    View details for PubMedID 30819837

  • Defining the elusive boundaries of chronic active Epstein-Barr virus infection. Haematologica Fernandez-Pol, S., Silva, O., Natkunam, Y. 2018; 103 (6): 924–27

    View details for PubMedID 29866887

  • A Survey of Somatic Mutations in 41 Genes in a Cohort of T-Cell Lymphomas Identifies Frequent Mutations in Genes Involved in Epigenetic Modification. Applied immunohistochemistry & molecular morphology : AIMM Fernandez-Pol, S., Ma, L., Joshi, R. P., Arber, D. A. 2018

    Abstract

    Here, we utilize a high throughput sequencing panel that covers several genes known to be recurrently mutated in certain T-cell lymphoma subtypes as well as genes frequently mutated in other hematolymphoid malignancies, including myeloid neoplasms. This panel was applied to formalin-fixed, paraffin-embedded tissue from 84 biopsies from 78 patients selected for this study. The biopsies included ones a with a diagnosis of T-cell lymphoma (n=79), including peripheral T-cell lymphoma not otherwise specified (PTCL-NOS; n=26) and angioimmunoblastic T-cell lymphoma (AITL; n=13), as well as 5 cases of atypical T-cell proliferations. KMT2C and KMT2D, which code for proteins involved in histone modifications, were the 2 most frequently mutated genes in our cohort and were altered across a range T-cell lymphomas. Mutations in TET2 and DNMT3A, which are involved in regulating DNA methylation, were also found in a variety of T-cell lymphoma categories. The RHOA G17V mutation that is frequently found in AITL was identified 5 of 13 (40%) cases of AITL and in 3 of 26 (12%) cases of PTCL-NOS, but not in biopsies involved by other T-cell proliferations. Our study adds to the already significant evidence from other investigators that, among T-cell lymphomas, the RHOA G17V variant is specific for AITL and PTCL-NOS. In contrast, variants in epigenetic modifier genes do not appear to be particularly specific for T-cell lymphoma subcategories evaluated in our study.

    View details for PubMedID 29629950

  • Scedosporium apiospermum infection of the urinary system with a review of treatment options and cases in the literature TRANSPLANT INFECTIOUS DISEASE Benamu, E., Yu, A., Xie, L., Fernandez-Pol, S., Liu, A. Y., Ho, D. Y. 2018; 20 (1)

    Abstract

    Infection with Scedosporium species is associated with a significant morbidity and mortality and is becoming increasingly common, especially in immunocompromised patients. We describe the presentation and successful management of an immunocompromised patient with Scedosporium apiospermum infection of the upper urinary tract system, a rare disease manifestation. The current literature on urinary tract scedosporiosis is further reviewed with emphasis on treatment options and limitations of current antifungal therapy.

    View details for PubMedID 29111602

    View details for PubMedCentralID PMC5871223

  • Immunohistochemistry for PAX7 is a useful confirmatory marker for Ewing sarcoma in decalcified bone marrow core biopsy specimens. Virchows Archiv : an international journal of pathology Fernandez-Pol, S. n., van de Rijn, M. n., Natkunam, Y. n., Charville, G. W. 2018

    Abstract

    PAX7 has been recently demonstrated to be a highly sensitive marker for Ewing sarcoma, and thus far has only been shown to label a relatively small set of other mesenchymal neoplasms. Because the processing of bone marrow core biopsies can often hinder the performance of immunohistochemical stains, we set out to determine if our laboratory's PAX7 staining protocol effectively detects Ewing sarcoma in Bouin's fixed, decalcified bone marrow core biopsies. We stained ten core biopsies involved by Ewing sarcoma, nine non-involved core biopsies, and 13 core biopsies involved by histologic mimics of Ewing sarcoma. Only the ten biopsies involved by Ewing sarcoma and four biopsies with rhabdomyosarcoma showed strong nuclear PAX7 staining. None of the other tumors demonstrated PAX7 expression. This study demonstrates that the PAX7 staining protocol used in our laboratory is a useful marker for Ewing sarcoma and other PAX7-positive tumors in decalcified bone marrow core biopsies.

    View details for PubMedID 30014288

  • Primary cutaneous anaplastic large cell lymphoma. Journal of cutaneous pathology Brown, R. A., Fernandez-Pol, S., Kim, J. 2017; 44 (6): 570-577

    Abstract

    Primary cutaneous anaplastic large cell lymphoma (PC-ALCL) is a CD30+ lymphoproliferative disorder (LPD) of the skin with a relatively good prognosis in the absence of high-stage disease. CD30+ LPDs comprise approximately 25%-30% of primary cutaneous lymphomas and as a group represent the second most common clonal T-cell neoplasm of the skin behind mycosis fungoides. Diagnosis of PC-ALCL relies strongly on clinicopathologic correlation given the potential morphologic, clinical and molecular overlap with the other cutaneous CD30+ LPD, lymphomatoid papulosis, and more aggressive hematolymphoid neoplasms.

    View details for DOI 10.1111/cup.12937

    View details for PubMedID 28342276

  • Immunohistochemistry for p53 is a useful tool to identify cases of acute myeloid leukemia with myelodysplasia-related changes that are TP53 mutated, have complex karyotype, and have poor prognosis. Modern pathology Fernandez-Pol, S., Ma, L., Ohgami, R. S., Arber, D. A. 2017; 30 (3): 382-392

    Abstract

    In this study, we evaluate the expression of p53 in core biopsies with acute myeloid leukemia and correlate the level of expression with acute myeloid leukemia subtype, TP53 mutation status, karyotype, and survival. Of the 143 cases evaluated, 71 fulfilled the WHO 2016 criteria for acute myeloid leukemia with myelodysplasia-related changes, 40 were acute myeloid leukemia-not otherwise specified, 25 were acute myeloid leukemia with recurrent genetic abnormalities, and 7 were therapy-related acute myeloid leukemia. By immunohistochemistry, 17% showed p53 expression in >5% of the cells. Of the 24 cases with >5% p53-positive cells, 17 were acute myeloid leukemia with myelodysplasia-related changes, 5 were acute myeloid leukemia-not otherwise specified, 1 was acute myeloid leukemia with recurrent genetic abormalities, and 1 was therapy-related acute myeloid leukemia. In cases for which data was available, expression of >5% p53-positive cells was significantly associated with genotype (n=67) and/or karyotype (n=130). Among the 115 cases for which clinical follow up was available, the overall survival of cases with p53 expression >15% (Median=102 days) was significantly shorter compared with cases with p53 expression ≤15% (Median=435 days). Within the acute myeloid leukemia with myelodysplasia-related changes group, this association remained significant, with cases with ≤15% p53-positive cells having a median overall survival of 405 days versus 102 days for cases with >15% p53-positive cells. Among acute myeloid leukemia with myelodysplasia-related changes cases with a complex karyotype, the finding of >15% p53-positive cells was significantly associated with worse overall survival. The poor prognosis associated with more than 15% p53-positive cells was independent of age and karyotype. In acute myeloid leukemia with myelodysplasia-related changes, p53 expression may be useful to infer TP53 mutation status, complex karyotype, and/or poor prognosis in situations where other modalities are not readily available.

    View details for DOI 10.1038/modpathol.2016.206

    View details for PubMedID 27934876

  • Immunohistochemistry reveals an increased proportion of MYC-positive cells in subcutaneous panniculitis-like T-cell lymphoma compared with lupus panniculitis. Journal of cutaneous pathology Fernandez-Pol, S. n., De Stefano, D. n., Kim, J. n. 2017; 44 (11): 925–30

    Abstract

    Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a malignant primary cutaneous T-cell lymphoma that shares significant clinical, histopathologic and immunophenotypic overlap with lupus erythematosus panniculitis (LEP).We performed immunohistochemistry for the MYC oncoprotein on 23 cases of SPTCL (1 CD8 negative) and 12 cases of LEP to evaluate if there are quantitative or qualitative differences in protein expression of this marker in these entities.In SPTCL cases, the percentage of all cells that were c-Myc positive ranged from 0.8% to 16%, with a mean of 5.0% and a median of 4.4%. In contrast, in the LEP cases, the percentage of c-Myc-positive cells in the cases ranged from 0.34% to 3.7%, averaged 1.4% and the median was 0.8%. The difference between the means of these 2 diagnostic categories was statistically significant. Fluorescence in situ hybridization performed on 4 cases of SPTCL with a relatively high level of MYC immunohistochemical staining, however, failed to demonstrate evidence of MYC rearrangement or amplification.Our work demonstrates that MYC expression levels differ between these 2 histologic mimics and suggests that this important oncoprotein may play a role in the pathogenesis of SPTCL.

    View details for PubMedID 28800143

  • Two cases of histiocytic sarcoma with BCL2 translocations and occult or subsequent follicular lymphoma. Human pathology Fernandez-Pol, S., Bangs, C. D., Cherry, A., Arber, D. A., Gratzinger, D. 2016; 55: 39-43

    Abstract

    Histiocytic sarcoma is rare and difficult to distinguish from histologic mimics such as myeloid sarcoma due to its relatively nonspecific immunoprofile. A subset of histiocytic sarcomas are clonally related to synchronous or metachronous follicular lymphomas. Interestingly, the histiocytic tumor component has been shown to harbor BCL2 gene translocations that are identical to those found in the lymphoma. We present one case of histiocytic sarcoma and initially occult follicular lymphoma in which detection of a BCL2 gene translocation helped support the diagnosis. We also provide follow up regarding a previously published case of histiocytic sarcoma with IGH/BCL2 fusion gene in which the patient subsequently developed follicular lymphoma and, later, diffuse large B-cell lymphoma. Our findings suggest that BCL2 gene translocations are a recurrent feature of a distinct subset of histiocytic sarcomas that are associated with follicular lymphoma; the follicular lymphoma component may be clinically occult at the time of diagnosis. Testing for an IGH/BCL2 translocation should be considered in the diagnostic workup of difficult to characterize neoplasms with histiocytic/monocytic morphology and immunoprofile.

    View details for DOI 10.1016/j.humpath.2016.04.004

    View details for PubMedID 27134111

  • Significance of myelodysplastic syndrome-associated somatic variants in the evaluation of patients with pancytopenia and idiopathic cytopenias of undetermined significance. Modern pathology Fernandez-Pol, S., Ma, L., Ohgami, R. S., Arber, D. A. 2016; 29 (9): 996-1003

    Abstract

    In this study, we set out to evaluate the frequency of mutations in 20 myelodysplastic syndrome-associated genes in 53 individuals with pancytopenia in which bone marrow evaluation failed to meet standard criteria for a diagnosis of myelodysplastic syndrome. These idiopathic pancytopenia cases were associated with no specific cause for their pancytopenia (n=28), aplastic anemia (n=13), pancytopenia attributable to liver disease (n=4), pancytopenia associated with autoimmune disease (n=4), and pancytopenia attributed to drug effect (n=4). We also selected 38 bone marrow aspirates from patients presenting with pancytopenia and meeting criteria for a diagnosis of myelodysplastic syndrome (n=21) or acute myeloid leukemia (n=17) as malignant comparison cases. Targeted sequencing of the 20 genes was performed on all cases. The idiopathic pancytopenia group had a lower average age (46 vs 66 years, P<0.0001) and a lower number of mutations per case that were statistically significant (0.81 vs 1.18, P=0.045). The frequency of cases with at least one mutation was higher for cases with a diagnosable myeloid neoplasm (68 vs 38%, P=0.012). Except for mutations in U2AF1, which was mutated in 5 of the 38 malignant cases (13.2%) and in none of the idiopathic pancytopenia cases (P=0.011), the frequency of mutations in the genes evaluated was not significantly different between idiopathic pancytopenia and malignant cases. Median and mean clinical follow-up for the idiopathic pancytopenia group was available for 444 and 739 days, respectively. Over this time frame, none of the idiopathic pancytopenia patients was diagnosed with a myelodysplastic syndrome or an acute myeloid leukemia. These findings provide further evidence that identification of mutations in several genes associated with myelodysplastic syndromes should not be used alone to support a diagnosis of a myelodysplastic syndrome.Modern Pathology advance online publication, 3 June 2016; doi:10.1038/modpathol.2016.100.

    View details for DOI 10.1038/modpathol.2016.100

    View details for PubMedID 27255165

  • Colonic plasmacytomas: a rare complication of plasma cell leukemia. Endoscopy Hang, C. T., Perumpail, R. B., Huang, R. J., Fernandez-Pol, S., Fernandez-Becker, N. Q. 2015; 47: E77-8

    View details for DOI 10.1055/s-0034-1390722

    View details for PubMedID 25926223

  • High-throughput Sequencing of Subcutaneous Panniculitis-like T-Cell Lymphoma Reveals Candidate Pathogenic Mutations. Applied immunohistochemistry & molecular morphology : AIMM Fernandez-Pol, S. n., Costa, H. A., Steiner, D. F., Ma, L. n., Merker, J. D., Kim, Y. H., Arber, D. A., Kim, J. n. ; 27 (10): 740–48

    Abstract

    Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a malignant primary cutaneous T-cell lymphoma that is challenging to distinguish from other neoplastic and reactive panniculitides. In an attempt to identify somatic variants in SPTCL that may be diagnostically or therapeutically relevant, we performed both exome sequencing on paired tumor-normal samples and targeted sequencing of hematolymphoid-malignancy-associated genes on tumor biopsies. Exome sequencing was performed on skin biopsies from 4 cases of skin-limited SPTCL, 1 case of peripheral T-cell lymphoma, not otherwise specified with secondary involvement of the panniculus, and 2 cases of lupus panniculitis. This approach detected between 1 and 13 high-confidence somatic variants that were predicted to result in a protein alteration per case. Variants of interest identified include 1 missense mutation in ARID1B in 1 case of SPTCL. To detect variants that were present at a lower level, we used a more sensitive targeted panel to sequence 41 hematolymphoid-malignancy-associated genes. The targeted panel was applied to 2 of the biopsies that were evaluated by whole exome sequencing as well as 5 additional biopsies. Potentially pathogenic variants were identified in KMT2D and PLCG1 among others, but no gene was altered in >2 of the 7 cases sequenced. One variant that was notably absent from the cases sequences is RHOA G17V. Further work will be required to further elucidate the genetic abnormalities that lead to this rare lymphoma.

    View details for DOI 10.1097/PAI.0000000000000683

    View details for PubMedID 31702703