Asymptomatic enlargement of the medial clavicle: report of five cases.

Five middle-aged women presented with unexplained chronic swelling at the medial clavicle. None of the patients recalled a history of trauma and none experienced pain or other symptoms associated with the swelling. In all cases, suspicion of tumor prompted referral to an orthopedic oncologist; two cases were biopsied before referral. Radiological studies demonstrated degenerative changes confined to the medial clavicle in three cases, exophytic overgrowth of the medial clavicle and adjacent manubrium in one case, and bilateral degenerative changes on both sides of the joint in one case. Prolonged follow-up supported the diagnosis of a benign, likely degenerative condition. These cases demonstrate the tendency for a variety of degenerative changes to manifest clinically as swelling at the medial clavicle. Inherent properties of the clavicle may predispose the medial clavicle to such changes. Recognition of this entity may prevent unnecessary testing or surgical biopsy of patients with this condition in the future. A thorough differential diagnosis of swelling at the medial clavicle is also presented.