BackgroundThe association of congenital anomalies of the female genital tract and carcinoma have been reported in the literature for the past century. Most cases reported involved uterus didelphys and associated carcinomas.CaseThe article describes well-differentiated adenocarcinoma and atypical endometrial hyperplasia associated with noncommunicating rudimentary uterine horns.ConclusionThe coexistence of Mullerian anomalies and carcinomas is relatively uncommon, and their existence in noncommunicating rudimentary uterine horns is rare. The following report describes a patient with carcinoma of the endometrium associated with complex atypical endometrial hyperplasia in noncommunicating rudimentary uterine horns.