Oral lipoma: Many features of a rare oral benign neoplasm

Introduction Lipomas are common benign soft tissue neoplasms composed of mature white adipocytes. They are the most common soft tissue mesenchymal neoplasms. However, they are relatively uncommon in the oral and maxillofacial regions. Their overall incidence in the oral cavity is thought to be between 1% and 4% of all benign oral lesions. Specific anatomic locations within the oral and maxillofacial region include the parotid region, buccal mucosae, lips, submandibular region, tongue, palate, floor- of-mouth and vestibule. Infrequent locations of orofacial lipomas include the maxillary bones, especially the mandible. Among lipomas, different subtypes can be described: simple lipoma, lipoma with chondro-osseous metaplasia, chondroid lipoma, fibrolipoma, infiltrating lipoma, angiolipoma, myolipoma of soft tissue, angiomyolipoma, spindle cell/pleomorphic lipoma (SCL/PM), myxolipoma, angiomyxolipoma, dendritic myxofibrolipoma, sialolipoma, congenital lipoma, hibernoma and atypical lipomatous tumor (ALT). Case Report We report an unusual large-sized lipomatous tumor located on the left side of floor-of-mouth, one of the rarest sites of intraoral lipoma. The final diagnosis of the lesion was fibrolipoma. The unusual characteristics of this case report were the large-sized dimensions of the neoplasm, which were 3 cm along the main diameter, and the histological subtype which is not common among the lipomas of the floor-of-mouth and of the oral cavity in general Conclusion A histological examination after removal of lipomas is imperative to exclude liposarcomatous degeneration. A detailed revising of the subtypes classification of the benign lipomatous tumours of the oral cavity is provided in this paper.