Musculoskeletal MCQ's

Question 1

Question:
A 58-year-old man has the sudden onset of severe pain in his left great toe. There is no history of trauma. On examination there is edema with erythema and pain on movement of the left 1st metatarsophalangeal joint, but there is no overlying skin ulceration. A joint aspirate is performed and on microscopic examination reveals numerous neutrophils and needle-shaped crystals. Over the next 3 weeks, he has two more similar episodes. On physical examination between these attacks, there is minimal loss of joint mobility. Which of the following laboratory test findings is most characteristic for his underlying disease process?

A. Hyperglycemia
B. Positive antinuclear antibody
C. Hyperuricemia
D. Hypercalcemia
E. High rheumatoid factor titer

Answer 1

Correct answer: C. Hyperuricemia

Explanation:
Needle-shaped crystals and neutrophils on joint aspirate are classic for gout.

Gout is caused by monosodium urate crystal deposition, typically in the 1st MTP joint.

The most characteristic lab finding is elevated serum uric acid (hyperuricemia).

Why not others?
A. Hyperglycemia – may coexist with gout, but not diagnostic.

B. Positive ANA – suggests lupus, not relevant here.

D. Hypercalcemia – associated with pseudogout (calcium pyrophosphate), which has rhomboid-shaped crystals.

E. High RF titer – seen in rheumatoid arthritis, not gout.

Conclusion: Sudden joint pain + needle-shaped crystals = Gout → Hyperuricemia (C).