A 72-year-old woman with a 15-year history of hypertension presents with chronic knee pain. Radiographs of the knees show linear calcification of the articular cartilage. Synovial fluid analysis under polarized microscopy reveals weakly positively birefringent rhomboid-shaped crystals. Which of the following is the most likely associated metabolic abnormality?
- A Iron overload (hemochromatosis) ✓
- B Hypercalcemia
- C Hyperuricemia
- D Hypomagnesemia
Correct answer: A. Iron overload (hemochromatosis)
Explanation
Calcium pyrophosphate deposition disease (CPPD) is characterized by positively birefringent rhomboid crystals and chondrocalcinosis on imaging. It is associated with hemochromatosis, hyperparathyroidism, hypomagnesemia, and hypophosphatasia. While hypomagnesemia is a valid association, iron overload (hemochromatosis) is the most classically tested association in Indian PG exams. Hyperuricemia causes gout, not CPPD.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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