Fat Free Pleomorphic Lipoma of Oral Cavity: A Rare Entity.

Pleomorphic lipoma is a rare, benign, soft tissue neoplasm that characteristically occurs as a subcutaneous mass in the posterior neck or upper back and rarely in the tonsillar fossa and oral cavity. Histologically, pleomorphic lipoma contains varying amounts of mature fat, areas of spindle and pleomorphic cells, floret giant cells and thick rope - like collagen in a myxoid stroma. Pleomorphic lipoma with scanty fatty elements is called the fat free variant of pleomorphic lipoma. The combination of meagre amount of fat and presence of pleomorphic elements gives a pseudosarcomatous picture under the microscope leading to misdiagnosis and over treatment. Here, we report a case of fat free pleomorphic lipoma, first of its kind in the oral cavity and discuss the diagnostic features and differential diagnosis.