Clinical Pathology

John Karl Frederiksen, M.D., Ph.D.

Assistant Professor Director, Hematology Laboratory University of Illinois at ChicagoPathology
Work Phone: (312) 996-1642 Work Fax: (312) 996-9574
Photo of John Karl Frederiksen M.D., Ph.D.

Biographical Info

Clinical Focus



Research and Educational Focus

Hematopathology, hematology test utilization



Stanford University (B.S., Chemistry)

University of Chicago Pritzker School of Medicine (M.D.)

University of Chicago (Ph.D., Biochemistry and Molecular Biology)


Post-Graduate Training:


University of Rochester Medical Center (Anatomic and Clinical Pathology)



University of Michigan Medical Center (Hematopathology)

University of Miami Miller School of Medicine (Molecular Genetic Pathology)


Board Certification:

Anatomic and Clinical Pathology


Molecular Genetic Pathology


Awards and Honors:

Best Teacher in the Pathology Residency Program, SUNY Upstate Medical University (2019-2020)

Teacher of the Year, University of Illinois at Chicago Pathology Residency Program (2022)


Selected Recent Publications:


Qu, C., Kunkalla, K., Vaghefi, A., Frederiksen, J. K., Liu, Y., Chapman, J. R., Blonska, M., Bernal-Mizrachi, L., Alderuccio, J. P., Lossos, I. S., Landgraf, R. & Vega, F. (2018).  Smoothened stabilizes and protects TRAF6 from degradation: A novel non-canonical role of smoothened with implications in lymphoma biology.  Cancer Lett 436, 149-158 (PubMed ID 30165192).


Choi, S. M., Frederiksen, J. K., Ross, C. W., Bixby, D. L. & Shao, L. (2017).  Philadelphia Chromosome-like Mixed-Phenotype Acute Leukemia Demonstrating P2RY8-CRLF2 Fusion and JAK1 Mutation.  Am J Clin Pathol 148, 523-528 (PubMed ID 29140408).


Weindorf, S. C. & Frederiksen, J. K. (2017).  IgG4-Related Disease: A Reminder for Practicing Pathologists.  Arch Pathol Lab Med 141, 1476-1483 (PubMed ID 29072949).


Frederiksen, J. K., Shao, L., Bixby, D. L. & Ross, C. W. (2016).  Shared clonal cytogenetic abnormalities in aberrant mast cells and leukemic myeloid blasts detected by single nucleotide polymorphism microarray-based whole-genome scanning.  Genes Chromosomes Cancer 55, 389-396 (PubMed ID 26865278).


Frederiksen, J. K., Sharma, M., Casulo, C. & Burack, W. R. (2015).  Systematic review of the effectiveness of fine-needle aspiration and/or core needle biopsy for subclassifying lymphoma.  Arch Pathol Lab Med 139, 245-251 (PubMed ID 25611108).


Frederiksen, J. K. & Ross, C. W. (2014).  Cytomegalovirus-associated hemophagocytic lymphohistiocytosis in a patient with myasthenia gravis treated with azathioprine.  Blood 123, 2290 (PubMed ID 24895699).

Categories: Clinical Pathology, Pathology