Giant Vulvar Mesonephric Duct Cysts Mimicking Malignancy: A Case Report and Diagnostic Challenge

Vulvar masses present a diagnostic challenge due to their wide spectrum from benign lesions to malignancy. Mesonephric duct cysts are rare benign lesions derived from Wolffian duct remnants that may clinically mimic vulvar cancer, particularly when large or symptomatic.

A 49-year-old multiparous woman presented with a painful vulvar mass that had progressively enlarged over one year. The patient reported that a similar lesion had been present for approximately 10 years. The lesion ruptured spontaneously several years earlier with purulent discharge and subsequently decreased in size. However, the patient did not seek medical attention or receive any treatment at that time. Progressive enlargement and pain developed during the preceding year, prompting medical consultation. Physical examination revealed multiple bilateral vulvar masses and uterine enlargement. Imaging suggested uterine leiomyoma. Due to high suspicion of malignancy, surgical excision of vulvar masses combined with total hysterectomy and bilateral salpingo-oophorectomy was performed. Histopathological examination revealed multiple mesonephric duct cysts without atypia or invasion and confirmed uterine leiomyoma.

Mesonephric duct cysts can closely mimic vulvar malignancy, especially when presenting as large and symptomatic masses. Histopathological evaluation remains the gold standard for diagnosis, and surgical excision is essential in cases with diagnostic uncertainty.