術前に鑑別し得た骨盤腹膜子宮内膜症性嚢胞の1例

It is unusual for endometriosis to form an extra-ovarian endometrioma. We presented a case of pelvic peritoneal endometriotic cyst, which pre-operatively was thought to be an extra-ovarian endometrioma. After a laparoscopic surgery, pathological examination revealed the mass to be a pelvic peritoneal endometrioma. [Case] A 35-yearold G2P0 woman visited a clinic hoping to get pregnant. She was diagnosed of a peritoneal cyst and came to our hospital for a detailed examination. Using sonography, a mass of about 5cm was detected in the posterior uterus, and both ovaries were normal. The MRI study suggested that the mass was either a denaturing myoma of the uterus or a secondary-ovarian endometrioma. We performed a laparoscopic operation for excision of the mass and sent it for a pathological examination. We did not detect any abnormal finding in the uterus and both adnexa. A diagnosis of an endometriotic cyst was made following the pathological examination. [Conclusion] We finally reached a definitive diagnosis by laparoscopic operation. This suggested that extra-ovarian endometrioma may be considered when a pelvic mass that is far from both ovaries is found, and MRI showed a typical endometriotic sign.