A 30-year-old man with hereditary spherocytosis undergoes laparotomy for symptomatic cholelithiasis. Which feature of his gallstones best supports a diagnosis of pigment rather than cholesterol stones?

• A Composed predominantly of crystalline cholesterol monohydrate
• B Formed by supersaturation of bile with cholesterol due to reduced bile salt secretion
• C Associated with obesity, female sex and multiparity
• D More likely to be radio-opaque on plain abdominal radiography ✓

Explanation

Pigment stones contain calcium bilirubinate as the major component, and a much higher proportion of them are radio-opaque on plain films compared with cholesterol stones, of which fewer than 20% are visible. Chronic hemolysis raises unconjugated bilirubin secretion into bile, favoring pigment stone formation. Option C describes the classic risk profile for cholesterol stones, and options A and B describe cholesterol stone pathogenesis, so all three are excluded by the hemolytic history.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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