Acute Onset of Elbow Swelling.

A 50-year-old man presented with swelling in his right elbow that began 10 days earlier. He had no history of injury to the arm, but he often rested his elbows on his desk at work. The elbow was not painful, and there was no arthralgia. He did not have a fever. His medical history was significant for chronic glomerulonephritis. He had been on hemodialysis for one year. Physical examination revealed a spherical, f luctuant swelling over the posterior portion of the right elbow (Figure 1). There was no redness or tenderness to palpation, and range of motion was normal.