Medial clavicular pain has a broad differential diagnosis that includes traumatic, atraumatic, and neoplastic etiologies. Dedicated imaging studies (eg, computed tomography, magnetic resonance imaging) play an essential role in evaluating and diagnosing disorders of the medial clavicle. In this article, we report a case of medial clavicular pain caused by a rare neoplasm, a solitary plasmacytoma of bone. This case illustrates the importance of accurate diagnosis that is facilitated by thorough evaluation and computed tomographic imaging of the medial clavicle.