Intravascular papillary endothelial hyperplasia: report of 2 cases and immunohistochemical study.

Intravascular papillary endothelial hyperplasia (IPEH) is a benign, nonneoplastic, vascular lesion. The main significance of the lesion lies in the fact that it may be mistaken for angiosarcoma. Oral lesions are uncommon and the present paper reports 2 cases of oral IPEH, in different sites. Histologically, the tissue was characterized by papillary fronds lined by proliferating endothelium. Immunohistochemically (IHC), the lesion was positive for CD34, smooth muscle actin (SMA), type I and IV collagen, vimentin, and laminin, but it was negative for CD105. Local excision was the treatment of choice. No recurrence was observed during a 1-year and 6-month follow-up period, respectively. The clinical, histological, and immunohistochemical characteristics are discussed.