Intravascular Papillary Endothelial Hyperplasia: Report of 4 cases with immunohistochemical findings

Abstract

Intravascular papillary endothelial hyperplasia (IPEH) is a benign endothelial proliferation, usually intravascular, that may mimic angiosarcoma. In this report, four new cases of IPEH involving the oral region are described. The affected sites were the lower lip, labial comissure and the submandibular region. After clinical evaluation, the complete removal of the lesions showed a circumscribed and soft mass. Histologically, the major feature was a reactive proliferation of endothelial cells composed of small papillary structures with hypocellular and hyalinized cores arising in an organized thrombus. Immunohistochemical staining for CD34 was strongly positive in endothelial cells. Vimentin and laminin immunolabelling were also consistent with a vascular origin. In order to verify the proliferative potential of the lesions, the Ki-67 antibody was used, revealing low percentage of labeled cells (<20%). No immunoreactivity for GLUT-1 was observed. Since the complete removal is curative, no additional treatment was necessary, and no signs of recurrence had been observed until now. Due to the particular features of IPEH, it is important for pathologists and clinicians to become familiar with this lesion. Additionally, the specific histological arrangement, including the absence of cellular pleomorphism, mitotic activity and necrosis, represents a guide to help in the differential diagnosis. Moreover, the vascular origin and the proliferative index should be assessed by immunohistochemistry in order to provide an accurate diagnosis.

Intravascular papillary endothelial hyperplasia: histomorphological and immunohistochemical features

“…IPEH is closely associated with thrombus formation in many cases. Previous reports have suggested that unique variation in thrombus organization contributes to IPEH [ 1 , 3 , 4 , 12 ], however the molecular basis for the development of IPEH in thrombus tissue has not been determined.…”

Oral Thrombus: Report of 122 cases with clinically descriptive data

“…But, it is difficult to affirm that the thrombus was secondary to the actinic cheilitis because actinic cheilitis occurred in only 6 of the 122 cases, with no other cases reported in the literature. On the other hand, the other lesions associated with thrombus in the present study are more likely to be secondary to the thrombus, such as PEH, a non-neoplastic lesion of unclear pathogenesis (23-25) and phleboliths (26). …”

Benign vascular lesions of the lips: Diagnostic approach

“…It is a non‐neoplastic lesion of unclear pathogenesis. Histologically, it represents a proliferation of endothelium‐lined papillary structure characterized by plump endothelium cells . It corresponded to 9% of our cases from the lips while in the skin and subcutaneous tissue it corresponds to 2% of the vascular tumors …”