A case of 5-year-old boy with pancreatoblastoma was reported. He was admitted to our hospital with a complaint of abdominal distension. A massive mass was palpated just below the xiphoid process on admission. Laboratory examination revealed elevated serum AFP (561.7ng/ml). X-CT and US showed an abnormal mass occupying the whole extent of the abdomen. Open biopsy was performed even though neuroblastoma was suspected preoperatively because of negative serum NSE and VMA. The tumor microscopically showed squamoid corpuscles surrounded by an acinar-like arrangement which is referred to as an organoid structure, Pancreatoblastoma was diagnosed histologically. Distal partial pancreatectomy concomitant with splenectomy and extirpation of the tumor was performed. Cyclophosphamide and ADM were administrated immediately after the operation and radiation therapy was performed 21 days after surgery. Serum AFP decreased from 561.7ng/ml to 0ng/ml. These combined therapies were useful in treatins the pancreatoblastoma.
