[Benign retroperitoneal cystic teratoma with postoperative chylous ascites--a case report].

A case of benign retroperitoneal cystic teratoma in a 62-year-old female is reported. The patient was admitted to our hospital for the purpose of extensive examination of a left abdominal mass. Radiological examinations including CT scanning revealed a large retroperitoneal mass arising in the left upper quadrant superior to the left kidney, containing cystic areas. The mass was removed by the thoracoabdominal approach under the diagnosis of cystic teratoma or liposarcoma. The margin of the mass was well demarcated and completely separated from other adjacent structures. Histological examination confirmed the diagnosis of benign cystic teratoma. From the 6th postoperative day, the discharge from a drainage tube, placed in the left retroperitoneal space, increased gradually and the discharge fluid became lipemic. The amount of daily discharge had a peak of approximately 400 ml on the 15th postoperative day. Total parenteral hyperalimentation was started on the 17th postoperative day under a diagnosis of chylous ascites. The amount of the discharge decreased and the drainage tube was removed on the 21st postoperative day.