A mixed form of intravascular papillary endothelial hyperplasia in an uncommon location: case and literature review.

Intravascular papillary endothelial hyperplasia (IPEH) is an unusual benign, non-neoplastic vascular lesion that usually occurs in skin, but is uncommon in the oral cavity. Herein, we review the pertinent literature of oraiiPEH and report a new mixed form. A 61-year- old man presented with an ulcerated nodule in the lingual portion of the gingiva related to the left mandibular canine. An excisional biopsy was performed presuming the clinical diagnosis of pyogenic granuloma. Histopathological analysis showed areas of granulation tissue consistent with pyogenic  granuloma. But in  addition, there  were thin-wall dilated vessels with papillary projections of endothelial cells producing vascular channels, associated with  an area of  organizing  thrombus. These microscopic findings led to the diagnosis of pyogenic  granuloma  associated with  IPEH. The immunohistochemical  reactions revealed a diffuse positivity of the vascular cells for CD-34 and smooth muscle actin antibodies.In addition,there was partial positivity for podoplanin and negativity for CD-1OS in the IPEH areas. No signs of recurrence were observed after 6 months of follow-up. The most prevalent site of IPEH in the oral region is the lower lip. IPEH is slightly more common in women and exhibits peaks of prevalence between the fourth and sixth decades of life.