A patient presents with acute hemolysis. Which finding is most specific for intravascular hemolysis rather than extravascular hemolysis?
- A Hemoglobinuria ✓
- B Spherocytes on peripheral smear
- C Splenomegaly
- D Elevated LDH
Correct answer: A. Hemoglobinuria
Explanation
Hemoglobinuria occurs when free hemoglobin exceeds haptoglobin binding capacity and is filtered by the kidneys, specific to intravascular hemolysis. Splenomegaly and spherocytes suggest extravascular hemolysis (splenic/hepatic clearance). LDH is elevated in both types. Hemosiderinuria (urine hemosiderin) is another specific marker of chronic intravascular hemolysis.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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