“…On reviewing the published literature, there is no doubt that the most common presentation of ACUM is dysmenorrhoea. 2,3,7,8,13,14,17,20,24,[36][37][38][39][40][41] The pain is usually felt in the ipsilateral site or the central pelvic area, especially during menstruation, and may also proceed the days before menstruation and may be accompanied by chronic pelvic pain. 2,3,8,29,36,37,41,42 Functional endometrial lining present in the accessory uterine cavity causes secretion of menstrual fluid during the period, and as the secreted fluid is placed in an enclosed space; it gets accumulated during the menstrual time, which during surgery we found as chocolate material inside the mass and chronic accumulation of this fluid leads to increased pressure within the cavity, and subsequent stretching of the cavity which produces pressure effect on the nerve fibers that are causing the pain and chronic stretched out cavity is the reason for having chronic pelvic pain.…”