Anastomosing hemangioma: A case report of a benign tumor often misdiagnosed as a malignant epithelioid angiosarcoma

Anastomosing hemangioma (AH), a rare benign genitourinary tract hemangioma is subject to frequent misdiagnosis due to its rarity and clinical, histological, and immunohistochemical similarities it shares with several diagnoses, including well-differentiated angiosarcoma (AS). This is particularly true of angiosarcoma, nearly identical to AH when presented in tissue samples of limited size. Lack of specific clinical and radiologic manifestations on initial preoperative assessment, coupled with limited diagnostic experience or awareness, can lead to misinterpretation of this entity, potentially leading to unnecessary clinical management. We present an initial misdiagnosis of AS which, upon review of the entire lesion, was identified as AH.