A 58-year-old man presents with flank pain, painless gross haematuria, and a palpable abdominal mass. Laboratory evaluation reveals haemoglobin of 19.2 g/dL with normal oxygen saturation. Which substance is most likely being produced ectopically by the tumour to explain this finding?
- A Parathyroid hormone-related peptide
- B Erythropoietin ✓
- C Adrenocorticotropic hormone
- D Serotonin
Correct answer: B. Erythropoietin
Explanation
Renal cell carcinoma classically presents with the triad of flank pain, haematuria, and palpable mass. It can cause secondary polycythaemia through ectopic erythropoietin production. PTHrP causes hypercalcemia in squamous cell carcinoma. ACTH causes Cushing syndrome in small cell lung cancer. Serotonin causes carcinoid syndrome.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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