2009 Volume 61 Issue 1 Pages 7-12
Uterine smooth muscle tumors are one of the most common types of gynecologic neoplasm. We report a case of a rare and benign uterine smooth muscle tumor with an unusual growth pattern, preoperatively diagnosed as a malignant ovarian neoplasm. A 57-year-old woman, with gravidity 2 and parity 2, presented with a pelvic mass that was detected during a screening examination for liver transplantation. On pelvic examination, a soft mass without elasticity was palpable in the pelvic cavity. Pelvic magnetic resonance imaging showed massive ascites and a multinodular mass, 20cm in size, with enhanced solid areas. The patient underwent laparotomy, which revealed that the mass was exophytic with a multinodular or multilobulated appearance and extended from the right uterine fundus into the right broad ligament. Supravaginal hysterectomy and bilateral salpingo-oophorectomy with tumor resection were performed. Frozen section of the mass revealed that it was a smooth muscle neoplasm, probably a leiomyoma. Histopathological analysis revealed many micronodules of benign smooth muscle cells, separated by fibrous connective tissue. No intramural or intravascular involvement was evident. Based on these findings, this tumor was diagnosed as a cotyledonoid dissecting leiomyoma. Preoperatively, these benign tumors have often been confused with malignant tumors, such as uterine sarcomas, due to their bizarre and sarcomatous gross appearance. Therefore, attention to the elasticity of the mass during pelvic examination and awareness of gynecologists regarding this rare tumor are important for accurate diagnosis. Furthermore, this type of lesion should be subjected to intraoperative frozen section analysis to avoid unnecessary treatment. [Adv Obstet Gynecol, 61 (1) : 7-12, 2009 (H21.2)]
