- A technique for laparoscopic excision of benign retroperitoneal tumors, including a teratoma and two cystic lesions, is described. Laparoscopic resection of a 12-cm retroperitoneal teratoma was accomplished with the patient in the left lateral decubitus position. Medial mobilization of the ascending colon and the duodenum was required for access to the lesion. Resections of two cystic lesions (measuring 20 cm and 12 cm) were performed with the patients in the lithotomy position. The colon required medial mobilization in both cases to gain access to the cysts. Once the cysts were dissected from surrounding structures, they were punctured, and the aspirated fluid was sent for cytologic analysis. There were no complications or conversions. Mean operating time was 122 minutes (range, 80-190). Patients were discharged 1 day after surgery, requiring only nonsteroidal anti-inflammatory medications for analgesia. Retroperitoneal tumors can be resected laparoscopically with careful preoperative investigation and meticulous laparoscopic technique. A major advantage of laparoscopic resections is that the patient recovers rapidly with minimal morbidity.