Rudimentary Horn Adenomyosis in A 20-Year-Old Patient With Unicornuate Uterus: A Case Report

Background: A unicornuate uterus with a rudimentary horn is a rare Mullerian anomaly with few cases reported in the literature. The symptoms vary depending on the functionality of the endometrial cavity and the presence of an obstruction. Adenomyosis is a disease defined as areas of endometrial glands and stroma present within the myometrium. Reports describing adenomyosis in relation to the Mullerian anomalies are scarce. Case Report: We present a 20-year-old middle eastern woman admitted for chronic pelvic pain and abdominal distension. Pelvic ultrasound revealed a unicornuate uterus with an adjacent mass of 10 x 8 cm. An MRI (Magnetic Resonance Imaging) was performed, and a left unicornuate uterus was demonstrated. On the right side, a large non-communicating rudimentary horn with features suggesting diffuse adenomyosis was found. Laparoscopic removal of the horn was performed successfully, and the extraction of the specimen was made by a power morcellation containment system. The patient was discharged uneventfully the second day after the surgery, and the pathology result confirmed the presence of diffuse adenomyosis. Conclusion: Non-communicating rudimentary horn is a rare finding manifesting as different symptoms in young women. The enlargement of the horn can have obstructive consequences on an active endometrium, and this would lead to the formation of a hematometra and the distension of the cavity, and sometimes adenomyosis.