Abstract
This is a report of a four-month-old male who was admitted complaining mainly of a mass in the left upper abdomen and abdominal distension, 219 cases of this disease collected from the Japanese literature are also reviewed. Retroperitoneal teratoma are often seen in the ovaries, testes and sacrococcygeal region, and they usually appear in the suckling period; 52.3% of the cases were under 6 months of age. Ultrasonic examinations, CT scans and measurement of alpha-fetoprotein are important in the diagnosis of this disease, and the preoperative diagnostic rate was 62.1%. The prognosis of the disease is generally good in benign cases, but 4.9% of the cases were malignant and these malignant cases still have a poor prognosis.
