Laparoscopic completely resection of retroperitoneal tumors diagnosed as ovarian tumors by preoperative imaging: report of two cases

Retroperitoneal neoplasms are relatively rare. We report two cases of retroperitoneal neoplasms diagnosed as ovarian tumors by preoperative imaging and approached by laparoscopic resection.Case 1: A 31-year-old woman had lower abdominal pain. Pelvic MRI showed an ovarian tumor measuring approximately 7 cm. Intraoperative findings revealed normal-sized ovaries and a tumor measuring approximately 7 cm in the right hemipelvis, surrounded by the retroperitoneal. We could resect the tumor without puncture. Histopathology revealed an epidermoid cyst.Case 2: A 56-year-old woman had hypermenorrhea. Pelvic MRI showed an ovarian tumor measuring approximately 7 cm. Intraoperative findings revealed normal-sized ovaries and a tumor measuring approximately 7 cm in the left hemipelvis, surrounded by the retroperitoneal. We could completely remove the tumor from the retroperitoneal space without any complications. Histopathology revealed a cellular schwannoma. Retroperitoneal teratomas are said that malignant change occurs in about 26%. Schwannomas are usually benign tumors; however, they have a few cases of malignant change and recurrence. Recently there are a lot of reports of retroperitoneal tumor in laparoscopic surgery. Laparoscopic surgery facilitates detailed observation, minimal invasion, and magnification, thus allowing faster postoperative recovery. In our cases, we could completely remove the masses without residual tumor. It is requirement that we should select appropriate procedure when intraoperative finding are retroperitoneal tumor thinking of malignant tumor.