Intravenous Leiomyomatosis Revisited

Intravenous leiomyomatosis (IVL) is a rare neoplasm of smooth muscle origin with the capacity for distant vascular and/or organ extension. The primary lesion is typically found in the uterus, with the most common extrauterine sites being pelvic/broad ligament vessels, and less often inferior vena cava, right heart chambers, and pulmonary vasculature. Extrauterine involvement can result in direct mass effect or vascular obstruction with associated clinical sequelae. Fourteen cases of IVL were identified in our pathology archives over a 25-yr period. Patient medical records and gross pathologic findings were reviewed. Histologic and related immunohistochemical slides (smooth muscle actin, desmin, CD31, CD34, and CD10) were re-evaluated by 2 gynecologic pathologists to confirm the diagnosis using conventional diagnostic criteria. Patient age at initial diagnosis ranged from 35 to 64 yr (mean: 46.1 yr), with a median age of 45 yr. Four cases demonstrated extrauterine extension, 2 cases were associated with disease recurrence, and 1 case was found to be extrauterine in origin (i.e. arising from the broad ligament). In summary, our study represents the fourth largest IVL cohort in literature to date, and contains the first case of IVL arising from the broad ligament in the absence of a uterine mass. IVL is a rare and potentially underdiagnosed neoplastic condition of smooth muscle origin that may result in significant morbidity when extrauterine vasculature or organs are involved. A high index of suspicion must be maintained, as the histologic diagnosis may be particularly challenging in cases in which the intracaval/intracardiac portion of the tumor is removed before the uterine IVL diagnosis, or a significant interval of time has elapsed since the initial IVL diagnosis was made. Prompt diagnosis combined with surgical excision has been shown to portend an increased survival rate and good overall prognosis in such cases.