Secondary dysmenorrhea due to a rudimentary, non-communicating functional uterine horn.

Unicornuate uterus with a rudimentary horn is a rare congenital Müllerian anomaly, which may lead to many obstetrical and gynaecological complications. This pathology occurs in approximately 1/100 000 women. A rudimentary horn forms due to insufficient development of the Müllerian duct. The diagnosis of this anomaly is usually delayed, as it remains asymptomatic until adolescence and its main symptom is dysmenorrhea.