Spindle cell/pleomorphic lipoma of the oral cavity.

We herein report a rare case of a lipomatous tumor of the buccal mucosa, showing intermediate morphological features between spindle cell and pleomorphic lipomas, for which the term spindle cell/pleomorphic lipoma is proposed. The presence of multinucleated floretlike cells may pose differential diagnostic problems, especially with spindle cell variant of well-differentiated liposarcoma. Morphological features helpful in the distinction between these tumors are emphasized. Although androgen receptors have been documented in most spindle cell lipomas, suggesting a potential pathogenetic role of sex steroid hormones, no immunoreactivity for androgen, estrogen, and progesterone receptors was obtained in our case. These findings would suggest a different pathogenetic pathway in spindle cell/pleomorphic lipoma of the oral cavity.