Mulerian duct agenesis with an occult adenomyotic rudimentary uterine horn

A unicornuate uterus is the most uncommon uterine anomaly of the female genital tract and usually associated with a rudimentary horn. We report a case presents the unusual condition where a segment of one uterine horn was functional in a patient who otherwise has Mulerian duct agenesis. A 17-year-old girl came to hospital with primary amenorrhea and cyclic pelvic pain. Pelvic ultrasonography and magnetic resonance imaging revealed a cystic mass in left pelvic wall. The cystic space was filled with hyperintense fluid on T1 and T2-weighted images. At laparoscopy the uterus and left ovary were not identified. Right ovary appeared normal. Instead of left ovary, functioning left rudimentary uterine horn was attached to the left pelvic wall. No endometriotic lesions were identified. Complete resection of the left uterine horn was performed. The nodule contained a small endometrial cavity and hematometra. Histologic study showed an adenomyotic uterine rudimentary horn. The patients were discharged on the second postoperative day. No intraoperative or postoperative complications or recurrence of pelvic pain occurred.