Lipomas, which are benign mesenchymal tumors originating from adipose tissue occur in the head and neck, mainly in the posterior neck. Although lipomas may occur anywhere in the soft tissues, the tongue is a rare location for these lesions ¹. Their occurrence in the tongue has been reported infrequently, accounting for only 0,3 per cent of all tongue neoplasms. Clinically, the tongue lipoma is presented as a asymptomatic, painless, soft slow growing solitary tumor with a smooth surface and well defined margins ^2,3. Here, we report a case of lipoma of tongue in a 60-year-old male patient, with its clinical presentation and the histopathological findings.

A 60-year-old Turkish man presented with a 4-month history of asymptomatic swelling on the right ventral side of his tongue. The mass had been growing slowly. His medical history was unremarkable. An examination of his tongue revealed a submucosal soft, non-tender nodular mass one cm in diameter on the right ventral side of the tongue. No ulceration was observed on the overlying mucosa (Figure. 1a). Other oropharyngeal, neck, and systemic examination findings were normal. Neither a computed-tomography (CT) study nor a magnetic resonance (MR) study was performed due to the clinically benign appearance of the mass. Under general anesthesia, the mass was excised through a vertical incision. A soft, encapsulated yellow mass was encountered following the mucosal incision, and the lesion was totally excised (Figure. 1b). A histopathological examination revealed mature adipocytes suggestive of lipoma; there was no increased mitotic activity or lipoblasts and no infiltration of the fibrous capsule (Figure. 1c). The patient showed no signs of recurrence at the end of a 6-month follow-up period.

Figure 1: (a) Preoperative view of submucosal tongue mass (arrow), (b) intraoperative view of the yellowish mass, (c) light micrograph of the specimen showing the mature adipocytes surrounded by a fibrous capsule (H&E,100X).

Lipomas are benign mesenchymal neoplasms that originate from mature adipose cells and are usually surrounded by a fibrous capsule. These tumors are the most commonly encountered soft tissue masses. Approximately 13% of all lipomas have been reported in the head and neck region and approximately 2% to 4% in the oral cavity. However, involvement of the tongue is quite rare. Tongue lipomas are often seen in middleaged patients and affect males predominantly, as in the present case ^1,4.

Lipomas are categorized as different subtypes, such as classic lipoma, lipomatosis, lipomatosis of the nerve, lipoblastoma, angiolipoma, myolipoma of the soft tissue, chondroid lipoma, spindle cell/pleomorphic lipoma, and hibernoma. Classic lipomas represent 80% of all lipomas, and this was the type seen in our case ^4,5.

Lipomas of the tongue are usually asymptomatic lesions. Symptoms, when present, depend on the rate of growth, the size, and the location of the tumor. Symptomatic tongue lipomas can cause dysphagia, limitations of tongue movement, dysarthria, and stridor ¹.

Radiological evaluation can help to clarify the diagnosis. In larger and deeper lesions, CT or MRI can show the extent of the mass and its infiltration into underlying structures. Intraoral ultrasonography has recently been shown to be simple and effective for tongue lesions ⁶. These tumors are diagnosed histopathologically. Histologically, classic lipomas consist of mature adipocytes embedded in a stroma of connective tissue and surrounded by a fibrous capsule ⁷.

Differential diagnosis of tongue lipomas include liposarcoma, fibroma, granular cell tumor, lingual ranula, minor salivary gland tumors, schwannomas, abscess, and ectopic lingual thyroid ⁸. Differential diagnosis with liposarcoma is important. Clinically, large size, deep localization, infiltration, and recurrence suggest malignancy. In the histopathological examination, lipoblast proliferation, pleomorphism, cellular hyperchromatism, and increased mitotic activity is important for the diagnosis of liposarcoma ⁹.

The treatment for lipomas is complete surgical excision. Recurrence is abnormal due to the well-defined demarcation of the fibrous capsule. In the present case, the mass was located in the anterior part of the tongue and could be removed easily ³.

In conclusion, although lipomas are the most frequently occurring mesenchymal tumors of the body, the lingual location is rare. Classic lipoma is the most frequent type in the tongue. The treatment choice for tongue lipoma is complete surgical excision. Recurrence has not been reported in the classic type lipoma