Anastomosing hemangioma of the kidney: A rare case report

Hemangiomas are benign vascular neoplasms primarily affecting the skin and soft tissues but can also occur in visceral organs, with the liver being the most common site. Renal hemangiomas are exceedingly rare, with fewer than 300 cases reported. Various subtypes, including cavernous, capillary, and anastomosing hemangiomas, have been identified. Anastomosing hemangioma (AH), a histological subtype of capillary hemangioma, was first described in 2009. AH has a distinctive histological architecture of anastomosing sinusoidal-like vascular spaces and often mimics angiosarcoma.

A 28-year-old male presented with an incidentally detected left renal mass found during an evaluation for abdominal pain and dyspepsia. The patient was asymptomatic with no history of hematuria or dysuria. Physical examination was unremarkable. Contrast computed tomography revealed a heterogeneously enhancing solid mass in the left kidney, suggesting a neoplastic etiology. Laparoscopic enucleation of the tumor was performed, and histopathological examination revealed a well-circumscribed tumor composed of irregular capillary-sized vascular spaces lined by plump endothelial cells with mild atypia. Immunohistochemical analysis showed positivity for CD34, CD31, and Factor VIII, confirming the diagnosis of anastomosing hemangioma. The patient has been under follow-up with no evidence of recurrence.

Anastomosing hemangioma of the kidney, although rare, is an important benign entity that can mimic malignant vascular tumors like angiosarcoma. Accurate diagnosis relies on histopathological examination and immunohistochemistry.

Despite its benign nature, AH often leads to overtreatment due to its diagnostic challenges. Increased awareness and reporting of AH cases are essential to improve diagnostic accuracy and management strategies.