Fat-Free Spindle Cell Lipoma of the Scalp: Lipoma Without a Lipogenic Component

Spindle cell lipoma (SCL) is a rare, benign subcutaneous neoplasm that typically occurs on the upper trunk or neck of middle-aged men. The diagnosis of SCL is often straightforward due to its characteristic clinical presentation and classic histologic features of admixed mature adipocytes and CD-34 positive bland spindle cells. However, the diagnosis can be elusive when low-fat and free-fat patterns occur. Due to the lack of lipogenic content and morphologic overlap, this rare tumor is often mistaken for other benign and malignant soft tissue tumors. The authors present the case of a middle-aged man with a fat-free SCL of the temporal scalp. To our knowledge, this is the first reported case in the literature ofa fat-free SCL involving the temporal scalp. With careful attention to the clinical context, histologic features, immunohistochemical profile, and cytogenetic abnormalities, the proper diagnosis of SCL without a lipogenic component can be achieved.