Capillary hemangioma is an acquired benign vascular tumor most common be found on skin and mucosal spaces of head and neck. Only very few cases of capillary hemangiomas have been reported in the abdomen, predominantly occurring as mucosal polyps in the bowel. Hence, we here share a case of retroperitoneal intravenous capillary hemangioma arising from gonadal vein treated by retroperitoneal en bloc excision by subcostal incision.

This 57-year-old female patient had past history of hypertension, diabetes mellitus, urolithiasis and left breast cancer post modified radical mastectomy on April, 1989. She was transferred to our urological clinic by breast surgeon because of incidental tumor measured 4.7 x 3.8 cm with heterogeneous enhancement over right retroperitoneum was found in regular following up computerized tomography (CT) scan. The differential diagnosis including gastrointestinal stromal tumor (GIST), carcinoid tumor, neurogenic tumor, metastasis, lymphadenopathy or other rare tumor after discussed with urological radiologist preoperatively. No remarkable symptoms were noted by the patient prior the surgery. Retroperitoneal tumor en bloc excision by subcostal incision was performed. The tumor was found medial to right upper third ureter, lateral to duodenum and above inferior vena cava (IVC) intraoperatively. Besides, one feeding vein arising from right renal vein, and another two feeding artery were also noted. Gross examination of the resection specimen revealed focal hemorrhagic and elastic sense. Microscopically, it showed a vascular tumor, composed of lobulation of proliferating capillaries within a delicate or loose fibrous stroma. This vascular tumor involves the large venous wall, demonstrated by actin immunostain and Elastic Van Gieson (EVG) stain, and adjacent soft tissues. It was compatible with the diagnosis of intravenous capillary hemangioma arising from a large vein (gonadal vein). The CD31 immunostain exhibits diffuse positivity on the endothelia of these vascular channels.

The patient discharged on postoperative day 5 without any perioperative complication. In following up CT scan 3 months postoperatively, no tumor recurrence was found.