A unique triple association: intravascular leiomyomatosis, benign metastasizing leiomyoma, and early-stage endometrial carcinoma

Abstract

Intravascular leiomyomatosis (IVL) and benign metastasizing leiomyoma (BML) are uncommon variants of uterine smooth muscle tumors that can demonstrate extrauterine spread despite their benign histological appearance. Both lesions are known to be estrogen-dependent, yet their coexistence with gynecologic malignancies—particularly endometrial carcinoma—is exceedingly rare. We present a 51-year-old postmenopausal woman who was admitted with progressive abdominal distension and ecchymotic skin changes over the abdominal wall. Radiologic evaluation revealed a large retroperitoneal mass with multiple solid pelvic lesions. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and resection of a para-aortic mass. Histopathological examination identified 3 concurrent entities: intravascular leiomyomatosis confined to the uterus, benign metastasizing leiomyoma involving para-aortic lymph nodes, and an incidental FIGO stage IA1 endometrioid adenocarcinoma confined to an endometrial polyp. Immunohistochemistry confirmed smooth muscle differentiation (Desmin, h-caldesmon), retained FH expression, low proliferative index (Ki-67 ≈ 2%–3%), and wild-type p53 pattern. Postoperative recovery was uneventful, and adjuvant hormonal suppression with letrozole was initiated. The patient remains disease-free during 6 months of follow-up. This case represents an exceptionally rare triple coexistence of IVL, BML, and early-stage endometrial carcinoma. Recognition of such unique associations broadens the understanding of estrogen-dependent uterine neoplasms and emphasizes the need for thorough histopathological and immunohistochemical evaluation. A multidisciplinary approach with long-term hormonal surveillance is recommended to detect recurrence or additional hormone-responsive lesions.