Leiomyomatoid angiomatous neuroendocrine tumor of the uterine myometrium with synchronous renal leiomyosarcoma: case report and review of the literature

Uterine smooth muscle tumors of uncertain malignant potential, also called STUMP, lack uniformity in their clinical course and therefore prognosis. A recently described variant of STUMP, leiomyomatoid angiomatous neuroendocrine tumor (LANT), contains both neuroendocrine cells and smooth muscle leiomyomatous vascular components. We describe a case of a LANT originating in the uterine myometrium, with a synchronous renal leiomyosarcoma, in a 53-year-old woman who presented with menometrorrhagia and unintentional weight loss. She underwent primary surgical treatment of both tumors and remains without evidence of disease 1 year later. Our discussion also includes a review of the literature guiding clinical management.