Cotyledonoid dissecting leiomyoma

Abstract

A 50-year-old woman with a history of abdominal myomectomy at 43 years of age presented with urinary frequency and pelvic pressure in April 2013. On physical examination the patient had a 20-week uterus with bilateral adnexal fullness extending into the recto-vaginal space. Her CA 125 level was 30.8. A pelvic MRI revealed a lobulated mass encasing the uterus, extending 2.5 cm above the umbilicus, filling both iliac fossa, and extending into the recto-vaginal space and laterally to the pelvic sidewalls. The differential diagnosis included a myxoid fibrosarcoma, a leiomyosarcoma, liposarcoma, and ovarian neoplasm. The patient underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. Intraoperatively, themass consisted of soft tissue with the appearance of placenta (Fig. 1). The intraoperative frozen sections were benign. The final pathology revealed a cotyledonoid dissecting leiomyoma (CDL) measuring 18 × 15 × 7 cm arising from the myometrial component. On histology, the tumor was composed of bland smooth muscle cells without atypia, necrosis, or mitotic activity, arranged in sweeping fascicles and edematous nodules. CDL was first described by David et al. [1] in 1975 as a “grapelike leiomyoma.” The stroma is rich in vessels, giving the tumor the appearance of placenta. Fingerlike projections of the tumor dissect through the uterine smooth muscle but the tumor cells lack atypia, mitoses, or coagulative tumor necrosis. Preda et al. [2] recommend pelvic MRI as the preferred modality for evaluating a mass suspicious for CDL because they characteristically appear iso-intense to the myometrium with intense postcontrast enhancement [2]. In a review of 41 cases of CDL, Smith et al. [3] reported the mean age at presentation was 45 years, with the youngest patient presenting at 23 years [3]. The majority of patients presented with pelvic pressure, pain, and menorrhagia. Six patients were treated with tumor resection alone, 22 with hysterectomy and removal of one or both ovaries, and 13 with hysterectomy with ovarian preservation. In