Clinical difficulties in diagnosis: a rare case of lipoma of the floor of the mouth.

Lipomas are soft tissue mesenchymal neoplasms that rarely occur in the oral and maxillofacial region. Their incidence in the floor of the mouth is very low. The authors present the case of a lipoma of the floor of the mouth, the diagnosis of this lesion was challenging as many clinical signs mimicked the appearance of a common ranula. Also the ultrasound imaging findings were not decisive and only during the operation the yellowish, solid and lobulated aspect of the lesion directed the surgeon to the correct treatment: a block resection of the mass was performed under local anesthesia with no complications. The patient remained asymptomatic with no evidence of recurrences in the postoperative follow-up period of 24 months. Histopathologically, the lesion was classified as a lipoma, a diagnosis based on the presence of mature adipose tissue with no cytologic atypia, subdivided by rare and thin septa of fibrous tissue with the presence of few blood vessels. The case reported highlights the difficulties in diagnosing lesions in the floor of the mouth and the necessity of including rare conditions like lipoma in the differential diagnosis.