Cytologic features of well-differentiated sclerosing liposarcoma in aspirated samples.

The histologic, cytologic and ultrastructural features of two cases of a rare variant of liposarcoma, the well-differentiated sclerosing type, are presented. These tumors are characterized by lipoblasts (in different stages of development), atypical fibroblasts, multinucleated floret cells, lipocytes and delicate, dispersed collagen. The differential diagnosis includes other types of liposarcoma and three benign lipomatous lesions: the pleomorphic lipoma, the atypical lipoma and the spindle cell lipoma. The latter three neoplasms are composed of fibroblasts, lipocytes and coarse collagen and may have typical lipoblastlike or fibroblastic cells. Given the difficulty in distinguishing these lesions, both cytologically and histologically, the clinical presentation and the tumor location become essential in rendering the diagnosis of sclerosing liposarcoma.