A 55-year-old man with renal cell carcinoma is found to have an elevated hemoglobin and hematocrit. Iron studies are normal. Which mechanism accounts for this finding?
- A Paraneoplastic autoimmune hemolysis
- B Tumor-induced bone marrow metastasis
- C Ectopic erythropoietin production by tumor cells ✓
- D JAK2 V617F mutation in hematopoietic stem cells
Correct answer: C. Ectopic erythropoietin production by tumor cells
Explanation
Renal cell carcinoma can produce ectopic erythropoietin, leading to secondary polycythemia. The JAK2 mutation is seen in primary polycythemia vera, which is a myeloproliferative neoplasm, not a paraneoplastic syndrome. Bone marrow metastasis from solid tumors typically causes cytopenias rather than polycythemia. Autoimmune hemolysis causes anemia.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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