Angiomyolipoma of the upper lip: case report and review of the literature.

Angiomyolipoma (AML) is a hamartomatous growth that usually affects the kidney. One third of patients with AML present with manifestations of tuberous sclerosis. Oral AML is rare with only 6 cases reported in the English-language literature. In the present case, AML was located in the upper lip of a 43 year-old woman. Clinically, it presented as a firm nodule, well circumscribed and measuring 1 x 2 cm. It was surgically excised. Histopathological analysis showed a lesion composed of an admixture of smooth muscle cells, blood vessels, and adipose tissue. The immunohistochemical study revealed positivity for vimentin, smooth muscle actin, pan specific muscle actin and desmin. CD68, CD34 and mast cell antibodies showed focal immunoreactivity. S100 protein, Ki-67, and HMB-45 were negative. Based on these histological and immunohistochemical features the diagnosis was of oral AML. No recurrence was observed after 2 years of follow-up.