A 63-year-old woman comes to your office complaining of a swollen and painful right knee. You aspirate the joint, and in the fluid are trapezoid-shaped, positively-birefringent crystals. Which of the following is not associated with her rheumatological condition?
1.Hemochromatosis
2.Hyperparathyroidism
3.Hyperuricemia
4.Hypomagnesemia
5.Hypophosphatemia
Solution
The crystals in the joint fluid are calcium pyrophosphate dihydrate crystals. She has pseudogout, also known as chondrocalcinosis. It is associated with hemochromatosis (A), hyperparathyroidism (B), hypomagnesemia (D), hypoposphatemia (E), and hypothyroidism. It is not associated with hyperuricemia (C–gout) or hypercalcemia.