Case History

66-year-old male with mild splenomegaly. HB: 17.5 g/dL; HCT: 52%; WBC: 10.1 10^3/cm; PLT: 948 10^3/cm. Blasts <1% in bone marrow. JAK2+

1 question 2 question

What is the diagnosis:

  1.         PMF, prefibrotic stage
  2.         PMF, fibrotic stage
  3.         ET
  4.         PV


d. Polycythemia Vera (PV)

Brief explanation of the answer:

This case meets the diagnostic criteria for PV; 1) HB; 17.5, 2) panmyelosis and megakaryocytic pleomorphism in the bone marrow (BM) and 3) JAK2 mutation. Prominent thrombocytosis can be seen in PV and BM morphology becomes very important to render the diagnosis which this case does not have ET morphology. Pre-fibrotic PMF is also in differential diagnosis due to hypercellularity in the BM; however pre-fibrotic PMF often shows myeloid hyperplasia with decreased erythropoiesis. Also this case does not show leukocytosis and/or leukoerythroblastosis.

Case contributed by Deniz Peker, M.D., Associate Professor of Pathology, Attending Physician in Hematopathology/Surgical Pathology in the Division of Laboratory Medicine, Director of the Flow Cytometry Lab at UAB Hospital