Resumen:
BACKGROUND: Intravascular adenomyomatosis (IA), characterised by endometrial-type glands or stroma embedded within smooth muscle tissue inside myometrial vessels, is a rare variant within the spectrum of uterine intravenous leiomyomatosis (IVL). CASE REPORT: A 45-year-old nulligravid woman presented with hypermenorrhoea and a large uterine mass radiologically interpreted as a degenerated fibroid. Histopathological examination of the hysterectomy specimen revealed a cellular leiomyoma with smooth muscle fibres and endometrial-type stroma within CD31-lined myometrial vessels, showing low mitotic activity and no atypia or necrosis. The postoperative course was uneventful, and the patient remained disease-free 12 months after surgery. DISCUSSION: Although IA is a benign lesion, intravascular growth may mimic malignancy both radiologically and histologically. A comprehensive review of the literature identified only 11 reported cases, most diagnosed postoperatively, all showing benign behaviour after complete excision. Awareness of this condition may prevent overtreatment and misclassification.