SYNOVIAL hemangioma is an unusual cause of knee effusions, but must be considered in the individual who has recurrent nontraumatic knee effusions. The diagnosis is best made by eliciting a characteristic history and physical examination, finding grossly bloody fluid on joint aspiration, and pursuing with arthrography or arthroscopy and then arthrotomy. The case described here was of 20 years' duration.
Report of a Case
A 22-year-old man was seen with the latest in a long series of recurrent nontraumatic left knee effusions.His first effusion had occurred at age 2 years when a swollen, painful left knee had suddenly developed without inciting trauma. On examination, he had been found to have a temperature of 39 °C, a moderate effusion of his left knee, and marked tenderness, especially over the medial femoral condyle. Roentgenograms had been normal; WBC count, 11,400/cu mm, with a normal differential cell count; and erythrocyte sedimentation rate,