Lipomas of the oral cavity: clinical and histopathologic study of 41 cases in a Brazilian population

This study evaluated the clinical and histopathologic aspects of 41 cases of oral lipomas diagnosed in a Brazilian population. All records from patients diagnosed with oral lipoma between 1970 and 2008 were reviewed. Histological sections were evaluated by light microscopy. There was a predominance of females (2.4:1), with a peak incidence between the sixth and seventh decade. The buccal mucosa was the most affected site (53.7%), followed by the buccal sulcus (14.6%) and tongue (9.8%). Tumor size ranged from 0.5 to 10 cm and the mean reported duration was 48 months. Histologically, the following variants were identified: lipoma (41.5%), fibrolipoma (34.1%), spindle cell lipoma (9.8%), sialolipoma (9.8%), osteolipoma (2.4%), and chondrolipoma (2.4%). Most tumors were well delimited, irrespective of the variant. Lipomas are rare tumors of the oral cavity. The characterization of new variants, such as sialolipomas, and the identification of histological subtypes in already known variants, such as low-fat and fat-free spindle cell lipomas, highlight the importance for careful microscopic evaluation of these tumors, which might be combined with immunohistochemistry in some cases.