Dr. Joshi is an instructor in molecular pathology, with training in clinical data science, molecular pathology, and clinical pathology. His clinical focus is molecular diagnostics for solid and hematologic neoplasms, and as part of Stanford Medicine's Molecular Genetic Pathology laboratory, Dr. Joshi has developed bioinformatic tools to monitor tumor mutation burden and gene/chromosome copy number variation from focused targeted sequencing panels. Dr. Joshi's research focuses on understanding the tumor-immune microenvironment by developing tools that connect underlying next-generation sequencing findings to computational image microscopy phenotypes.

Academic Appointments

  • Instructor, Pathology

Honors & Awards

  • Stanford Clinical Data Science Fellow, Departments of Biomedical Data Science and Pathology (9/1/2019 - 8/31/2020)

Professional Education

  • Fellowship, Stanford University, Molecular Genetic Pathology (2019)
  • Residency, Stanford University, Clinical Pathology (2020)
  • M.D., Perelman School of Medicine, University of Pennsylvania (2016)
  • Ph.D., Perelman School of Medicine, University of Pennsylvania, Immunology (2013)
  • B.A., Columbia College, Columbia University, Biochemistry (2006)

All Publications

  • A predictive tool for identification of SARS-CoV-2 PCR-negative emergency department patients using routine test results. Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology Joshi, R. P., Pejaver, V., Hammarlund, N. E., Sung, H., Lee, S. K., Furmanchuk, A., Lee, H. Y., Scott, G., Gombar, S., Shah, N., Shen, S., Nassiri, A., Schneider, D., Ahmad, F. S., Liebovitz, D., Kho, A., Mooney, S., Pinsky, B. A., Banaei, N. 2020; 129: 104502


    Testing for COVID-19 remains limited in the United States and across the world. Poor allocation of limited testing resources leads to misutilization of health system resources, which complementary rapid testing tools could ameliorate.To predict SARS-CoV-2 PCR positivity based on complete blood count components and patient sex.A retrospective case-control design for collection of data and a logistic regression prediction model was used. Participants were emergency department patients > 18 years old who had concurrent complete blood counts and SARS-CoV-2 PCR testing. 33 confirmed SARS-CoV-2 PCR positive and 357 negative patients at Stanford Health Care were used for model training. Validation cohorts consisted of emergency department patients > 18 years old who had concurrent complete blood counts and SARS-CoV-2 PCR testing in Northern California (41 PCR positive, 495 PCR negative), Seattle, Washington (40 PCR positive, 306 PCR negative), Chicago, Illinois (245 PCR positive, 1015 PCR negative), and South Korea (9 PCR positive, 236 PCR negative).A decision support tool that utilizes components of complete blood count and patient sex for prediction of SARS-CoV-2 PCR positivity demonstrated a C-statistic of 78 %, an optimized sensitivity of 93 %, and generalizability to other emergency department populations. By restricting PCR testing to predicted positive patients in a hypothetical scenario of 1000 patients requiring testing but testing resources limited to 60 % of patients, this tool would allow a 33 % increase in properly allocated resources.A prediction tool based on complete blood count results can better allocate SARS-CoV-2 testing and other health care resources such as personal protective equipment during a pandemic surge.

    View details for DOI 10.1016/j.jcv.2020.104502

    View details for PubMedID 32544861

  • 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
  • Targeted deep sequencing of cell-free DNA from body cavity fluids with malignant, suspicious, and benign cytology Yang, S., Libiran, P., Jones, C., Joshi, R., Lau, H., Stehr, H., Longacre, T., Allison, K., Zehnder, J., Long, S., Berry, G., Kunder, C. NATURE PUBLISHING GROUP. 2019
  • Falsely high sirolimus concentrations due to everolimus cross-reactivity in the Siemens sirolimus immunoassay: Corrective actions implemented CLINICA CHIMICA ACTA Bowen, R., Rieta, R., Joshi, R., Lee, R. C. 2019; 489: 162–63
  • Pharma-Oncogenomics in theEra of Personal Genomics: A Quick Guide to Online Resources and Tools. Advances in experimental medicine and biology Joshi, R. P., Steiner, D. F., Konnick, E. Q., Suarez, C. J. 2019; 1168: 103–15


    The past two decades have seen unprecedented advances in the field of oncogenomics. The ongoing characterization of neoplastic tissues through genomic techniques has transformed many aspects of cancer research, diagnosis, and treatment. However, identifying sequence variants with biological and clinical significance is a challenging endeavor. In order to accomplish this task, variants must be annotated and interpreted using various online resources. Data on protein structure, functional prediction, variant frequency in relevant populations, and multipleother factors have beencompiled in usefuldatabasesfor this purpose.Thus, understanding the available online resourcesfor the annotation and interpretationof sequencevariantsis critical to aid molecular pathologistsand researchers working in this space.

    View details for DOI 10.1007/978-3-030-24100-1_7

    View details for PubMedID 31713167

  • Transfusion Management of Conjoined Twins Undergoing Surgical Separation: A Single Center Experience with Three Sets of Thoraco-Omphalopagus Twins over Ten Years Tsang, H., Kuan, C., Boltz, M., Hartman, G., Joshi, R. P., Panigrahi, A., Andrews, J. WILEY. 2018: 122A–123A
  • The Brief Case: Confirmed Positive HIV-1 Serologic Screening but Undetectable RNA Virus Load in a Pregnant Woman. Journal of clinical microbiology Joshi, R. P., Gomez, C. A., Steiner, D., Aziz, N., Pinsky, B. A. 2017; 55 (12): 3316–20

    View details for PubMedID 29180504

  • Closing the Brief Case: Confirmed Positive HIV-1 Serological Screening but Undetectable RNA Virus Load in a Pregnant Woman. Journal of clinical microbiology Joshi, R. P., Gomez, C. A., Steiner, D., Aziz, N., Pinsky, B. A. 2017; 55 (12): 3566–67

    View details for PubMedID 29180505