Mesonephric adenocarcinoma of the vagina masquerading as a suburethral cyst

Mesonephric adenocarcinoma (MA) of the vagina is an extremely rare tumour of the female genital tract. There are currently 22 reported cases in the published literature. Consequently, its pathophysiology and disease progression remain poorly understood. A 63-year-old woman presented with a history of a swelling in her vagina. Two-dimensional pelvic floor ultrasound and MRI demonstrated a multiloculated cyst with no malignant features. Initial workup provided a working diagnosis of a suburethral cyst. The diagnosis of MA was made on histology after excision of the cyst. Subsequent postoperative investigation showed no spread of the disease. The patient completed a course of prophylactic brachytherapy to prevent the possibility of any recurrence of disease. Due to its rarity, it remains difficult to diagnose MA of the vagina even on histological analysis. We would therefore recommend a low threshold to excise or perform tissue biopsy of unspecified vaginal masses.