A 65-year-old presents with splenomegaly, anemia, tear-drop-shaped RBCs, and a dry tap on bone marrow aspiration. Core biopsy shows extensive reticulin fibrosis. The JAK2 V617F mutation is positive. The diagnosis is:

• A Hairy cell leukemia
• B Chronic myeloid leukemia
• C Essential thrombocythemia
• D Primary myelofibrosis ✓

Explanation

Primary myelofibrosis (PMF) presents with teardrop erythrocytes (dacrocytes), leukoerythroblastic blood picture, massive splenomegaly due to extramedullary hematopoiesis, and a fibrotic, hypocellular marrow producing 'dry tap.' JAK2 V617F is positive in ~50% of PMF cases. Hairy cell leukemia has BRAF V600E mutation and shows hairy lymphocytes; CML has the Philadelphia chromosome; ET has high platelets without significant fibrosis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.