Subcutaneous spindle cell/pleomorphic lipoma: A case report of a peculiar tumor entity.

Spindle cell/pleomorphic lipoma (SCL/PL) is a rare histologic subtype of lipoma. It occurs in a characteristic clinical settings, arising mainly in middle-aged and older men in subcutaneous tissue of the posterior neck, upper back, and shoulders (shawl region). In women, it much more comonly develops outside the typical shawl location. The author describes a 66-year-old man with a subcutaneous tumor mass in the left back side of the neck. It consisted of bland spindle cell population situated in a fibromyxoid stroma containing thick collagen bundles. Scattered pleomorphic and multinucleated floret-like giant cells were also found. The neoplastic cells showed CD34-positive/S100-negative immunophenotype. A diagnosis of a SCL/PL was established. Subcutaneous SCL/PL is an unfamiliar tumor entity to most dermatologists. Despite the worrisome name it is a clearly benign lesion with no tendency to recur after surgical treatment. The present paper is excellent for demonstrating its unique clinical and histomorphological characteristics. [ABSTRACT FROM AUTHOR]