Accessory Cavitating Uterine Masses/Malformation: An Important Differential in Women With Intractable Dysmenorrhea and Chronic Pelvic Pain Across All Ages

AIM: Accessory cavitated uterine malformation or mass (ACUM) is a rare and under-recognized cause of dysmenorrhea and chronic pelvic pain (CPP). Various diagnostic criteria have been proposed; patients may present with atypical features. This study aimed to describe the clinical presentation, diagnostic challenges, and management outcomes of ACUM. METHODS: Retrospective analysis of prospectively collected data was done at a tertiary care institution over 6 years. All women diagnosed with ACUM were included. Clinical presentation, imaging, preoperative diagnosis, intraoperative picture, and management outcomes were analyzed. RESULT: Eighteen women were enrolled. The median age at presentation was 26.5 years (18-46), with 17 in the reproductive age group and one postmenopausal. The median duration of symptoms was 4 years (2 months to 11 years). Dysmenorrhea with prominent pain on one side, localized to the side of the lesion, was the predominant symptom, occurring in 17/18 (94.4%). Of these, 10/18 (55.6%) experienced both CPP and dysmenorrhea, 7/18 (38.9%) had only dysmenorrhea. Only CPP was reported in 1/18 (5.6%), woman with postmenopausal ACUM. On initial 2D-USG, one case was correctly diagnosed, while 5/18(27.8%) were misdiagnosed as rudimentary horn, 7/18(38.9%) as degenerated fibroid, 4/18(22.2%) as endometrioma, and 1/18(5.6%) as dermoid cyst. Diagnosis was confirmed on further imaging with 3D-USG or MRI in 11/18 (61.1%) cases. Seventeen women underwent surgical management, with 16/17 had excision, and one postmenopausal woman was treated by laparoscopic aspiration. CONCLUSION: ACUM is an important differential of intractable dysmenorrhea or CPP, especially if pain is localized to either side, even in postmenopausal females.