A case of renal anastomosing hemangioma with significant enlargement during seven years follow-up

Anastomosing hemangioma (AH) is a rare benign vascular tumor of the kidney that can mimic malignant renal tumors on imaging. We report a case of renal AH showing marked enlargement during long-term follow-up. A 56-year-old man was found to have a left renal mass during evaluation for renal dysfunction. The lesion had been diagnosed as hemangioma by percutaneous biopsy and managed conservatively. During follow-up, the tumor enlarged from 35 mm to 90 mm, raising suspicion of malignancy and leading to nephrectomy. Histopathological examination confirmed AH, highlighting the need for careful radiological surveillance.