PLEOMORPHIC LIPOMA: A RARE VARIANT OF LIPOMA IN AN UNUSUAL CLINICAL PRESENTATION

A 57-year-old white female patient complaining of a 5-day painless smooth and pedunculated nodule covered by healthy oral mucosa at the lingual retromolar region was submitted to excisional biopsy. The differential clinical diagnoses comprised fibroma and fibrous hyperplasia. Histologic aspect revealed a benign neoplasia characterized by proliferation of mature adipocytes and spindle cells. These cells presented elongated nuclei and were arranged in small blocks through the fibrous connective tissue. The final diagnosis was pleomorphic lipoma. Oral lipoma is an uncommon mesenchymal neoplasia that usually affects the buccal mucosa and has a benign course without recurrence. The pleomorphic variant is a remarkably rare form of lipoma in oral mucosa, and most of these lesions were described in the tongue. The fusiform component of this lesion is similar to other lesions, requiring special attention at morphologic examination to exclude well-differentiated liposarcoma or immunohistochemical staining (CD34 e S100) to exclude other spindle cell lesions.