Clinical Focus

  • Anatomic and Clinical Pathology

Academic Appointments

Professional Education

  • Fellowship: Stanford University Pathology Fellowships (2021) CA
  • Board Certification: American Board of Pathology, Anatomic and Clinical Pathology (2020)
  • Residency: LACplusUSC Medical Center Dept of Pathology (2020) CA
  • Medical Education: Hofstra University Zucker School of Medicine (2015) NY

All Publications

  • Case-Control Study of Individuals with Discrepant Nucleocapsid and Spike Protein SARS-CoV-2 IgG Results. Clinical chemistry Wang, H. n., Wiredja, D. n., Yang, L. n., Bulterys, P. L., Costales, C. n., Röltgen, K. n., Manalac, J. n., Yee, J. n., Zehnder, J. n., Shi, R. Z., Boyd, S. D., Pinsky, B. A. 2021


    Laboratory-based methods for SARS-CoV-2 antibody detection vary widely in performance. However, there are limited prospectively-collected data on assay performance, and minimal clinical information to guide interpretation of discrepant results.Over a two-week period, 1080 consecutive plasma samples submitted for clinical SARS-CoV-2 IgG testing were tested in parallel for anti-nucleocapsid IgG (anti-N, Abbott) and anti-spike IgG (anti-S1, EUROIMMUN). Chart review was conducted for samples testing positive or borderline on either assay, and for an age/sex-matched cohort of samples negative by both assays. CDC surveillance case definitions were used to determine clinical sensitivity/specificity and conduct receiver operating characteristics curve analysis.There were 52 samples positive by both methods, 2 positive for anti-N only, 34 positive for anti-S1 only, and 27 borderline for anti-S1. Of the 34 individuals positive for anti-S1 alone, 8 (24%) had confirmed COVID-19. No anti-S1 borderline cases were positive for anti-N or had confirmed/probable COVID-19. The anti-N assay was less sensitive (84.2% [95% CI 72.1-92.5%] versus 94.7% [95% CI 85.4-98.9%]) but more specific (99.2% [95% CI 95.5-100%] versus 86.9% [95% CI 79.6-92.3%]) than anti-S1. Abbott anti-N sensitivity could be improved to 96.5% with minimal effect on specificity if the index threshold was lowered from 1.4 to 0.6.Real-world concordance between different serologic assays may be lower than previously described in retrospective studies. These findings have implications for the interpretation of SARS-CoV-2 IgG results, especially with the advent of spike antigen-targeted vaccination, as a subset of patients with true infection are anti-N negative and anti-S1 positive.

    View details for DOI 10.1093/clinchem/hvab045

    View details for PubMedID 33720347

  • SARS-CoV-2 Neutralization Resistance Mutations in Patient with HIV/AIDS, California, USA. Emerging infectious diseases Hoffman, S. A., Costales, C., Sahoo, M. K., Palanisamy, S., Yamamoto, F., Huang, C., Verghese, M., Solis, D. C., Sibai, M., Subramanian, A., Tompkins, L. S., Grant, P., Shafer, R. W., Pinsky, B. A. 2021; 27 (10)


    We report persistent severe acute respiratory syndrome coronavirus 2 infection in a patient with HIV/AIDS; the virus developed spike N terminal domain and receptor binding domain neutralization resistance mutations. Our findings suggest that immunocompromised patients can harbor emerging variants of severe acute respiratory syndrome coronavirus 2.

    View details for DOI 10.3201/eid2710.211461

    View details for PubMedID 34296992

  • Clear Cell Variant of Solid Pseudopapillary Neoplasm of the Pancreas: A Report of a Rare Variant and Review of the Literature INTERNATIONAL JOURNAL OF SURGICAL PATHOLOGY Costales, C., Mehta, A., Kulkarni, S., Larson, B. K. 2019; 27 (5): 535-540


    The clear cell variant of solid pseudopapillary neoplasm (ccSPN) of the pancreas was first described in 2006. In this article, we report a case of this rare variant and review the few published reports. Both the current and previous reports show that ccSPN has several morphologic differences from conventional SPN, including clear vacuoles, fewer pseudopapillary formations, more solid/diffuse architecture, less hemorrhage, and fewer cholesterol clefts. Some of these features peculiar to ccSPN, such as solid/diffuse architecture, have been proposed to suggest aggressive behavior, though reports of ccSPN are rare and often have limited clinical follow-up. ccSPN also appears to occur more frequently in males than conventional SPNs. These clinical and pathologic features lead to unique set of differential diagnostic considerations for ccSPN, including metastatic renal cell carcinoma, perivascular epithelial cell tumor, and clear cell variants of other carcinomas. These unique features, atypical differential, and uncertain prognostic ramifications all make ccSPN an important variant to be aware of and report.

    View details for DOI 10.1177/1066896919833790

    View details for Web of Science ID 000474904800015

    View details for PubMedID 30845855

  • A Real Pain: Diagnostic Quandaries and Septic Arthritis JOURNAL OF CLINICAL MICROBIOLOGY Costales, C., Butler-Wu, S. M. 2018; 56 (2)


    Rapid diagnosis and treatment of an infected joint are paramount in preserving orthopedic function. Here, we present a brief review of the many challenges associated with the diagnosis of both septic arthritis and prosthetic joint infections. We also discuss the many laboratory tests currently available to aid in the accurate diagnosis of joint infection, as well as emerging diagnostics that may have future utility in the diagnosis of these challenging clinical entities.

    View details for DOI 10.1128/JCM.01358-17

    View details for Web of Science ID 000423163200014

    View details for PubMedID 29187561

    View details for PubMedCentralID PMC5786716

  • Lung Adenocarcinoma with Miliary Metastases and Left Femur Pathologic Fracture: an Unusual Case Mimicking Disseminated Tuberculosis. HSS journal : the musculoskeletal journal of Hospital for Special Surgery Khadem, N., Costales, C., White, E. A., Patel, D. B., Tomasian, A., Matcuk, G. R. 2017; 13 (2): 201-206

    View details for DOI 10.1007/s11420-016-9538-0

    View details for PubMedID 28690472

  • Asian-variant intravascular large B-cell lymphoma. Proceedings (Baylor University. Medical Center) Su, D. W., Pasch, W., Costales, C., Siddiqi, I., Mohrbacher, A. 2017; 30 (2): 186-189


    Intravascular large B-cell lymphoma (IVLBCL) is a rare and deadly malignancy involving the growth of lymphoma cells within vessel lumina of all organ types. IVLBCL is further divided into the hemophagocytic Asian variant and a classical Western variant. Both variants are difficult to diagnose by imaging, and although diagnostic criteria have been developed to guide workup, histopathological examination remains imperative. Treatment of IVLBCL remains difficult given the high mortality of the disease, but rituximab has emerged as a promising therapeutic option when combined with various cytotoxic regimens. The two main variants of IVLBCL generally manifest in their respective Asian or Western populations, and crossover between ethnicities is rare. We present the second described case of Asian-variant IVLBCL in an African American individual.

    View details for PubMedID 28405077

  • Malakoplakia of the Thyroid Gland: A Case Report and Review of Literature INTERNATIONAL JOURNAL OF SURGICAL PATHOLOGY Vitkovski, T., Costales, C., Chen, S., Saltman, B., Kahn, L. 2015; 23 (4): 308-312


    Malakoplakia is a rare granulomatous disease that most commonly occurs in the urinary tract. It is characterized by sheets of histiocytes with granular basophilic inclusions and Michaelis-Gutmann bodies. We present an exceedingly rare case of malakoplakia of the thyroid in a 54-year-old Caucasian woman on immunosuppressive therapy for renal transplant performed in 1994.

    View details for DOI 10.1177/1066896915569915

    View details for Web of Science ID 000354407700010

    View details for PubMedID 25663335