A Case of Cotyledonoid Dissecting Leiomyoma With Associated Disseminated Peritoneal Leiomyomatosis: The Significance of Frozen Section in Identification of This Unusual Entity.

Cotyledonoid dissecting leiomyoma (CDL) is a rare variant of uterine leiomyoma. The tumor is benign, but the appearance and growth pattern are unusual and alarming. Disseminated peritoneal leiomyomatosis (DPL) is another rare tumor that can mimic malignancy. The occurrence of these two tumors in a single case is even rarer and has not been found in the literature to the best of our knowledge. We report a case of CDL with DPL in a 43-year-old Nepalese woman who presented with abdominal pain and per vaginal bleeding. Ultrasound showed a heterogeneous hypoechoic mass of size 25.1 × 15.5 × 9.4 cm in the pelvic cavity. A CT scan of the abdomen and pelvis revealed an ill-defined, heterogeneously enhancing lesion in the pelvis around the uterine fundus with a peritoneal nodule. The intraoperative frozen section evaluated the peritoneal deposit to be benign. Due to the large size of the uterine mass, a total abdominal hysterectomy and a bilateral salpingo-oophorectomy were performed. Macroscopically, a large heterogeneous intramural and exophytic mass was observed, which, on histopathology and immunohistochemistry (IHC), revealed the benign smooth muscle origin of the tumor. In the seven-month follow-up period, no recurrence or any other related complications were found. It is important to recognize this rare variant of leiomyoma with the possibility of dissemination that can also happen in leiomyoma to prevent aggressive and inappropriate overdiagnosis and overtreatment. Whenever possible, it is advisable to perform a frozen section biopsy and IHC for the correct diagnosis.