Liposarcoma (atypical lipomatous tumors) of the vulva: a clinicopathologic study of six cases.

Liposarcoma, the most common soft tissue sarcoma, usually arises in the limbs, trunk, or abdomen, but very rarely in the vulva. Six cases of liposarcoma of the vulva are described here. They were characterized by their occurrence in predominantly middle-aged women (median age 52), variable size, and focally infiltrative margin. The preoperative clinical diagnosis for all patients was of a benign lesion, with a diagnosis of lipoma in two. Four of six cases had the usual histologic appearance of a well-differentiated liposarcoma/atypical lipomatous tumor with variation in adipocyte size, adipocytic nuclear atypia, and occasional lipoblasts. Two of the six cases had a very unusual histologic appearance, not previously described, with an admixture of neoplastic bland spindle and round cells along with adipocytes showing variation in size as well as numerous mainly bivacuolated lipoblasts. Liposarcomas of other types were not identified. Follow-up data were available for five of the six patients and all were treated by excision with no additional treatment. Four showed no sign of recurrence at 12, 14, 18, and 84 months. One tumor was incompletely excised, regrew over a 10-year period, was re-excised, and showed no further recurrence 31 months thereafter. Liposarcoma can occur in the vulva, is predominantly of the well-differentiated subtype, can show an unusual histologic appearance with an admixture of spindle cells and numerous lipoblasts, and seems to have a behavior similar to these tumors in other anatomic locations.