Abstract
BACKGROUND: Disseminated peritoneal leiomyomatosis is a rare condition characterized by the dissemination of histologically benign leiomyomas within the peritoneal and retroperitoneal cavities. Intra-abdominal findings can resemble the peritoneal dissemination of gynecologic or gastrointestinal malignancies. Disseminated peritoneal leiomyomatosis has been predominantly reported in patients with a history of gynecological treatment or during pregnancy. Herein, we present a case of disseminated peritoneal leiomyomatosis diagnosed incidentally following the torsion of a uterine fibroid in a patient without prior gynecological treatment. This presentation is extremely rare, particularly because it occurred in a postmenopausal woman and manifested as an acute abdomen without any prior gynecologic intervention. CASE PRESENTATION: A 53-year-old Japanese woman (gravida 2, para 2) was under observation for multiple uterine fibroids without treatment. The patient was postmenopausal and had no significant medical, surgical, family, or psychosocial history, and no history of hormonal therapy or other gynecologic interventions. The patient presented with sudden-onset lower abdominal pain and was emergently transported to our hospital with a suspected diagnosis of torsion of an ovarian tumor or pedunculated subserosal uterine fibroid. Emergency laparotomy revealed a 15 cm pedunculated subserosal fibroid with 180° of torsion. In addition to the multiple uterine fibroids, multiple nodules were observed in the omentum and pelvic peritoneum. Therefore, a total abdominal hysterectomy, bilateral salpingo-oophorectomy, partial omentectomy, and pelvic peritonectomy were performed. Histopathological examination revealed multiple uterine, omental, and peritoneal leiomyomas, leading to the diagnosis of disseminated peritoneal leiomyomatosis. Postoperative computed tomography demonstrated small residual nodules on the pelvic floor that were also suspected to be leiomyomas. The patient remains under continuous follow-up, with no evidence of disease progression over more than 3 years of postoperative surveillance. Although the patient presented with fever, tachycardia, and elevated inflammatory markers, no infectious workup such as blood cultures was performed because the clinical presentation and computed tomography findings strongly supported torsion as the primary etiology; however, infectious evaluation should also have been considered. CONCLUSION: When unexpected intraoperative peritoneal dissemination is encountered, disseminated peritoneal leiomyomatosis should be considered in the differential diagnosis alongside malignancy, recognizing that it can develop even in a patient without prior gynecologic treatment, which is extremely rare. Careful intra-abdominal assessment and appropriate surgical decision-making are essential. Given that only isolated reports have described disseminated peritoneal leiomyomatosis presenting with acute abdomen or torsion-related symptoms, the present case further underscores the exceptional rarity of this clinical scenario.