Cotyledonoid dissecting leiomyoma with peritoneal dissemination

Cotyledonoid dissecting leiomyoma (CDL) is a rare benign uterine leiomyoma that macroscopically shows multinodular placenta-like growth. Its border with the myometrial layer is unclear, making it clinically difficult to differentiate from uterine sarcoma. CDL is often misdiagnosed. We report a case of CDL in which a subserosal myoma was suspected preoperatively and an abdominal myomectomy was performed. However, due to intraoperative findings and intraoperative rapid histopathological diagnosis, the procedure was changed to total hysterectomy. Peritoneal dissemination had also occurred and was resected simultaneously. It has been reported that CDL is generally a disease with good prognosis and that fertility preservation may be considered depending on the case. On the other hand, some cases of large tumours have caused peritoneal dissemination. We did a literature review of CDL and compared a group with peritoneal dissemination who underwent disseminated resection simultaneously and a group without peritoneal dissemination. We found that the tumour diameter was significantly greater in the peritoneal dissemination group.