Benign fibrohistiocytoma (xanthomatous variant) of the acromion. A case report and review of the literature.

A number of fibrous lesions involving bone display almost identical histologic appearances yet may represent either reactive or neoplastic conditions, resulting in a confusing nomenclature and possible diagnostic confusion. We report the case of a young man with no significant previous medical history who presented with a painful lesion in the left shoulder, which consisted almost entirely of xanthomatous material. We discuss the possible differential diagnosis of this lesion and why benign fibrous histiocytoma is the preferred terminology for this lesion. To our knowledge, this is the first reported case of a benign fibrous histiocytoma involving the acromion in an adult.