Adenomyotic cyst mimicking a congenital Müllerian anomaly: Diagnosis and treatment with laparoscopy.

A 28-year-old woman presented with a 1-year history of severe progressive dysmenorrhea following suction evacuation and tubal ligation. Sonography showed a bicornuate uterus with hematometra in the left horn. Hysteroscopy ruled out a diagnosis of a congenital Müllerian anomaly, as both ostia appeared normal. Under laparoscopy, a mass was seen on the left fundal region near the insertion of the round ligament, and needle aspiration of a chocolate-colored fluid confirmed the diagnosis of an adenomyotic cyst. The cyst was excised. The patient recovered well and has been symptom-free since surgery. Adenomyotic cyst is a rare entity in young women and must be differentiated from obstructive Müllerian anomaly. Laparoscopy is the preferred minimally invasive modality for managing this rare disorder.