Clinics in diagnostic imaging (87). Subcutaneous lipoma

A 40-year-old man presented with recent increase in size of a painless long-standing soft mass over the right shoulder. Magnetic resonance (MR) imaging showed a lobulated mass located within the subcutaneous layer overlying the deltoid muscle. It was homogeneously T1-hyperintense, T2-hyperintense, and non-enhancing. Signal characteristics were those of a simple lipoma. The diagnosis was confirmed on histopathological examination of the excised specimen. Musculoskeletal lipomas are discussed, with emphasis on their characteristic appearances on various imaging modalities, and illustrated by additional examples.