Leiomyosarcoma with synchronous clear cell ovarian carcinoma

Uterine leiomyomas are typically considered benign lesions. Despite aggressive management, they can be unpredictable and eventually exhibit disease recurrence several years following initial treatment.

We report a case involving a 55-year-old woman who was treated for a uterine leiomyoma at an outside medical institution 20 years ago. In November 2009, she presented to our gynecologic oncology service with a complex mass. Following surgery, the patient was diagnosed with a 16 cm ovarian mass and a synchronous leiomyosarcoma; the latter neoplasm appeared to originate from a previously resected uterine leiomyoma.

The coexistence of these two lesions is exceedingly rare. We suspect that the leiomyosarcoma developed from either the patient's original uterine leiomyoma or leiomyomatosis peritonealis disseminata.