Extravascular type of intravascular papillary endothelial hyperplasia mimicking parotid gland neoplasia and the possible role of ferritin in the pathogenesis: A case report.

Intravascular papillary endothelial hyperplasia (IPEH) is defined as a vascular lesion characterized by extensive proliferation of vascular endothelial cells. This lesion was first described by Pierre Masson in 1923 as intravascular hemangioendothelioma. The most frequent sites of involvement are the skin and subcutis. IPEH comprises ~2% of the vascular tumors of the skin and subcutaneous tissue and it has a predilection for the head, neck, trunk and the extremities. The diagnosis is based on histopathology. We herein present the second case of Masson's tumor of the parotid gland described in literature. The patient was a 70-year-old female. Magnetic resonance imaging revealed an irregular lesion with smooth margins, initially considered to be compatible with pleomorphic adenoma. Immunohistochemical analysis revealed positivity of the tumor cells for ferritin heavy and light chains, vimentin and CD31. The aim of the present study was to emphasize the immunohistochemical characteristics and briefly discuss the potential role of ferritin in the pathogenesis of IPEH.