Radiological Case of the Month

A 10 ⅔-year-old boy had a two-week history of left hip tenderness and a one-week history of rapid development of masses over the left lateral hip and right lateral foot. A temperature of 38.9°C (102°F) and decreased appetite were also noted. Patient history and family history were unremarkable. On physical examination a 6×8-cm, firm, rubbery, slightly mobile mass over the left greater trochanter and a 2 × 4-cm, firm, rubbery mass over the right fifth metatarsal were present. A slightly decreased range of motion of the left hip and a normal range of motion of the right foot were noted. Both masses were nonfluctuant. Roentgenograms of the left hip (Fig 1) and right foot (Fig 2) were obtained. Initial laboratory tests demonstrated the following serum levels: calcium, 9.8 mg/dL (2.45 mmol/L); phosphorus, 7.3 mg/dL (2.36 mmol/L); alkaline phosphatase, 14.2 Bodansky units/dL (76 U/L); urea nitrogen, 8 mg/dL (3 mmol/L of