A giant uterine leiomyoma simulating an ovarian mass in a 16-year-old girl: a case report and review of the literature.

Uterine leiomyomas are extremely rare neoplasms in the pediatric and adolescent population. We report a case of a giant uterine leiomyoma measuring 30 cm in the largest diameter in a 16-year-old girl. To our knowledge this is the largest leiomyoma reported thus far in women under the age of 20 years. The patient was admitted to our hospital for the investigation of menstrual disorders, vaginal bleeding and progressive abdominal enlargement. Preoperative diagnosis was ovarian malignancy. Myomectomy was performed. Histopathologic study of the tumor showed an otherwise typical leiomyoma, both grossly and microscopically, with extensive hydropic and myxomatous degeneration and areas of prominent vessels, suggesting an angiomatous neoplasm. Leiomyomas in teenagers often exhibit histological features favoring the diagnosis of malignancy, and should be evaluated with extreme caution. The management of leiomyomas in these young patients should be conservative for the preservation of fertility.