Right endometrioma is related with more extensive obliteration of the Douglas pouch

Objective To investigate that endometrioma is an asymmetric disease with left lateral predisposition as compared to other benign ovarian cyst and also, whether endometrioma side is related with endometriosis severity. Methods Operative and histopathologic findings of 340 women who underwent cystectomy for treatment of endometriotic ( n = 239) and nonendometriotic ovarian cysts ( n = 101) by laparoscopy ( n = 268) or laparotomy ( n = 72) between January 2005 and August 2009 were evaluated retrospectively. We compared left and right sided distribution of endometriotic and nonendometriotic ovarian cysts, and we also investigated the extent of endometriotic foci, obliteration of pouch of Douglas and endometriosis stage according to the revised American Fertility Society classification of endometriosis to assess whether endometrioma side is related with the severity of endometriosis. Results Of 239 women with endometriosis, endometrioma was found in the left ovary ( n = 109), right ovary ( n = 58) and bilaterally ( n = 72). Of 101 control group women functional and dermoid cysts were found in the left ovary ( n = 48), right ovary ( n = 43) and bilaterally ( n = 10). Among women with unilateral ovarian endometrioma ( n = 167) a left cyst (63.3%) was found more frequently than a right cyst (34.7%) ( P