Intraperitoneal Third Müllerian Duct Mimicking a Hydrosalpinx: Laparoscopic Diagnosis and Treatment

Background: The most frequent congenital anomalies of the genital tract in women are caused by irregular development of the Müllerian ducts. At present, known Müllerian anomalies include abnormal ductal unification, aplasia, and vaginal cysts. No cases of duplicated Müllerian ducts in females have been described previously. Case: A 33-year-old woman presented with what appeared to be a hydrosalpinx on preoperative ultrasound. It actually was a unique case of an intraperitoneal tubular structure suggestive of a monolateral duplicated Müllerian duct. The uterus, fallopian tubes, and ovaries were all normal. There was an intraperitoneal tubular structure of 15 × 3 cm in the left hemipelvis, running medially to the infundibulopelvic ligament and the fallopian tube, and ending in the left vaginal fornix. Diagnostic vaginoscopy showed a millimetric communication between the tubular intraperitoneal mass and the vagina. The tubular structure was excised laparoscopically. Results: Histopathologic and immunohistochemical evaluations revealed a typical Müllerian duct epithelium with multilayered columnar ciliated cells with positivity for both estrogen receptors and CD 10. Conclusions: The anatomical structure described herein is difficult to categorize because there is a lack of previous similar observations. Based upon a thorough evaluation—including macroscopic anatomy and microscopic and immunohistochemical analysis—the diagnosis was a monolateral complete duplication of the Müllerian duct. Other observations are needed to confirm these findings and possibly gain new insight into the clinical presentation of genital anomalies in women. (J GYNECOL SURG 34:49)