A 35-year-old woman, on hemodialysis for chronic renal disease, complains of pain in the hands. On examination, the joints are normal with no inflammation or tenderness on palpation. Lab values reveal a low calcium, high phosphate, and high PTH level. What is the most likely diagnosis? (See Figure below.)

The diagnosis is secondary hyperparathyroidism as a consequence of the chronic renal disease. Calcium deposits are seen in the periarticular areas of the fourth and fifth metacarpophalangeal, third proximal interphalangeal, and fourth distal interphalangeal joints. There is slight soft tissue swelling, especially, of the fourth and fifth metacarpophalangeal joints. Calcification in scleroderma is subcutaneous in location. In gout if monosodium urate is deposited it could appear as a soft tissue mass.