Spontaneous ruptured middle colic artery aneurysm with concurrent renal cell carcinoma

We present the first reported case of spontaneous ruptured middle colic art ery aneurysm in a patient who has concurrent hypervascular tumor which has a potential for rupturing. A 68-year-old Japanese man was admitted with abd ominal pain and hypervascular renal tumor which developed in the subcapsula r cortex and protruded outward. The next morning after admission, anemia ra pidly progressed and severe abdominal pain developed. Emergency laparotomy was performed for a preliminary diagnosis of ruptured hypervascular renal t umor. However, the renal tumor was not ruptured but a ruptured middle colic artery aneurysm was found. The aneurysm measured 3.0x2.0cm in greatest dia meter and was resected. Three weeks later, nephrectomy for hypervascular re nal tumor was electively performed, Histologically, the tumor was clear cel l carcinoma. In the present case, the diagnosis of ruptured middle colic ar tery was extremely difficult.