The role of differential diagnosis in intravascular papillary endothelial hyperplasia of the sinonasal cavity mimicking angiosarcoma: A case report.

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's tumour, is an unusual vascular lesion characterized by the proliferation of endothelial cells. The principal significance of IPEH is its clinical and radiological resemblance to angiosarcoma, resulting in a potential misdiagnosis and overtreatment. The aim of the present study is to report a rare case of IPEH of the right maxillary sinus, focusing on the radiological and histopathological features of the neoplasm and their role in the differential diagnosis with angiosarcoma. Herein we present a case of a 67-year-old woman with history of right-sided nasal obstruction. A computed tomography scan indicated opacity in the right maxillary sinus and significant bony erosion, and an magnetic resonance imaging revealed a highly vascularized polylobed neoplasm, suggesting a malignant neoplasm. The mass was removed surgically through a combined open and endoscopic approach. A perioperative biopsy excluded malignancy and histological examination was consistent with IPEH. IPEH in the sinonasal cavity is an extremely rare condition in which differential diagnosis serves a central role due to its close clinical and radiological resemblance to angiosarcoma. Awareness of IPEH is recommended for a correct diagnosis, and in order to avoid unnecessarily aggressive treatment.