A 78-year-old man was admitted to the hospital because of anal bleeding. CT scan showed a mixed density tumor at the body of the pancreas and varices around the tumor. Angiography (arterial phase) revealed the hypervascular tumor with irregular border. And co-lateral vessels developed around the tumor at venous phase. Endiscopic retrograde pancreatography was performed unsuccesfully. Leiomyosarcoma of the pancrease was suspected and a laparotomy was performed in Januuary 1997. The tumor infiltrated into the multiple organs, including stomach, spleen, transeverse colon, left adreanal gland and capsule of left kidney, and extended to the main pancreatic duct. Thus a distal pancreatectomy and a resection of the invaded organs were performed. The main tumor was 9×8×3cm in size and the extending tumor to the duct was 4.5cm in length. Histologically, the tumor was an islet cell tumor with evident trabecular and ribbon-like structures. The immunochemical stainings for chromogranin A, Glimerius, insulin, glucagon and somatostatin were negative, and hormonal concentrations measured in the operation were normal. Finally this tumor was diagnosed as non-functional islet cell carcinoma. No recurrence has been detected in a year and eight month since the operation.