Musculoskeletal images. Clavicular soft-tissue mass.

a mass in the anterior part of his right shoulder. Examination revealed a well-circumscribed lesion over the central one-third of the right clavicle, measuring approximately 8 × 7 cm. The mass was firm, nonpulsatile and immobile, appearing to be contiguous with, and fixed to, the clavicle. A plain radiograph of the clavicle is shown in Fig. 1 and a representative magnetic resonance image in Fig. 2. At operation, careful dissection revealed a cystic bluish mass with an extremely thin shell over overlying bone and periosteum (Fig. 3). The lesion was aspirated with a hypodermic syringe, and the lining was noted to collapse away from the surrounding bone. The lesion was entered and curettage done quickly to control bleeding. The periosteum was closed once hemostasis was ensured. The specimen was sent for pathological examination and culture. The term aneurysmal bone cyst was popularized by Jaffe and LichtSurgical Images Imagier chirurgical