The unicornuate uterus with an occult adenomyotic rudimentary horn.

We report 2 case of an atypical variant of unicornuate uterus in 2 adolescent patients with severe dysmenorrhea. Pelvic ultrasonography and magnetic resonance imaging identified a normal uterine contour. On the right side within the uterine fundus, a nodule was detected with a small hypoechogenic content. At laparoscopy the uterus and adnexae appeared to be normal. No endometriotic lesions were identified. Hysteroscopy identified a single regular cervical canal and a uterine cavity resembling that of a left unicornuate uterus, with a single regular left tubal ostium. Complete resection of the right uterine nodule along with an ipsilateral salpingectomy was performed. The nodule contained a small endometrial cavity and hematometra. Histologic study showed a cavitated adenomyotic uterine rudiment. The patients were discharged on the second postoperative day. No intraoperative or postoperative complications or recurrence of pelvic pain occurred.