Spindle Cell Lipoma of the Oral Cavity: A Clinico-Pathologic Analysis of 35 Reported Cases

Spindle-cell lipoma (SCL) is a variant of lipoma, usually presenting in the neck or trunk. SCL of the oral cavity is rare. Some cases of oral SCL have been reported; however, the clinico-pathologic characteristics of oral SCL are still unknown. Here we report on 2 cases and review 33 cases of oral SCL published in the literature. The patients were 23 men and 12 women, with a mean age of 55 years (range 23 88 years); there were no children. Tumor sites included: tongue (n = 13), cheek/buccal mucosa (n = 11), floor of mouth (n = 5), lip (n = 2), hard palate (n = 2), alveolar ridge (n = 1), and maxilla (n = 1). The mean tumor size was 20.87 mm (range 3 50 mm), smaller than extra-oral lesions. Thirty-three patients (94%) presented with a single lesion that was circumscribed and composed of mature adipocytes admixed with bland spindle cells. The spindle cells were strongly immunoreactive for CD34, whereas the adipocytes were negative. The main differential diagnosis is atypical lipoma/well-differentiated liposarcoma. All lesions underwent local excision and recurrences are rare. Oral SCL do not seem to differ from their extra-oral counterpart, which are much more common and larger in size. SCL should be included in the differential diagnosis of oral cavity mesenchymal tumors.