Angioleiomyoma affecting the lips: report of 3 cases and review of the literature.

Angioleiomyoma is an uncommon benign soft tissue tumor usually found in the lower extremities and rarely observed in oral tissues. It is microscopically characterized as a proliferation of smooth muscle cells intermingled with abundant vascular channels. Oral angioleiomyomas affect mostly the lips, palate, buccal mucosa and tongue, and appears as a submucosal painless nodule. Upper lip is seldom affected and only few cases have been reported. We report three additional cases of angioleiomyoma affecting the lips of elderly patients. All lesions were asymptomatic and presented as submucosal nodules of approximately 1cm. Microscopic analysis on H&E sections revealed similar pattern in all cases, showing well-circumscribed and encapsulated tumors characterized by proliferation of smooth muscle cells and large amount of wide vascular spaces of varying sizes. Most tumor cells were immunoreactive for a-smooth muscle actin, desmin and HHF-35. CD34 was also positive on the endothelial cells. All patients were surgically treated and no recurrence was observed so far. The oral pathologists and clinicians should consider this entity when assessing nodular lesions on upper lip.