Mesothelial Inclusion Cyst of Uterus in a Primary Infertility Patient

This is to report a rare case of a large uterine mesothelial cyst that was previously misdiagnosed as hydrosalpinx in transvaginal ultrasound and that was diagnosed in a primary infertility patient. In a 31-year-old, primary infertility case, transvaginal sonography revealed an oblong, anechoic, partially septate complex lesion, which was located behind the uterus towards the left side of it, and it was preoperatively diagnosed as left hydrosalpinx measuring about 7.24 cm × 3.3 cm. Laparoscopic surgery revealed a large cystic lesion on the posterior wall of the uterus. Laparoscopic uterine cystectomy was performed after aspiration of the fluid, which was found to be straw coloured. The patient’s recovery was good. Histopathological examination confirmed the diagnosis of uterine mesothelial cyst. Uterine mesothelial cysts are not common, and they are abnormal pelvic masses. Clinicians should be aware of these lesions, and this awareness can contribute to better diagnosis as well as better and timely management of the case.