A 60-year-old man presents with fatigue, pruritus after hot showers, and early satiety. Examination shows splenomaly. Hb 18.5 g/dL, Hct 58%, WBC 14,000/µL, platelets 520,000/µL. Erythropoietin level is low. JAK2 V617F is positive. Bone marrow shows panmyelosis without significant fibrosis. According to WHO criteria, which two major criteria confirm the diagnosis of polycythemia vera?

• A Leukoerythroblastic blood picture and absence of BCR-ABL1
• B Low serum erythropoietin and bone marrow panmyelosis
• C Thrombocytosis >450,000/µL and splenomegaly
• D Hemoglobin >16.5 g/dL in men and JAK2 V617F mutation ✓

Explanation

WHO 2016 criteria for PV require three major criteria: (1) Hb >16.5 g/dL (men) or >16.0 g/dL (women) or elevated red cell mass; (2) bone marrow biopsy showing panmyelosis; (3) JAK2 V617F or JAK2 exon 12 mutation. Low EPO is a minor criterion. Thrombocytosis >450,000 is a minor criterion. The combination of elevated hemoglobin threshold plus JAK2 mutation is sufficient with bone marrow panmyelosis to confirm PV.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.