BackgroundBladder exstrophy occurs in approximately 1 in 35,000 live births and is associated with an increased incidence of bladder cancer.The primary mucinous adenocarcinoma of the bladder is an extremely rare urologic entity, which is found in less than 2% of all urinary bladder tumours and is often presented as metastatic. This is the first case in literature of a primary mucinous adenocarcinoma of an unreconstructed exstrophic bladder.Case presentationA 55-year old male patient was diagnosed with a primary mucinous adenocarcinoma of an unreconstructed exstrophic bladder. Examination of the entire gastrointestinal tract shown there were not other primary cites. Immunohistochemistry confirmed the nature of the tumour. The patient underwent a radical cystoprostatectomy with en block bilateral pelvic lymphadenectomy, urinary diversion with a cutaneous ureterostomy and epidpadias repair.ConclusionAdult bladder exstrophy and epispadia correction is a very rare practice in urology due the fact that this congenital disease is diagnosed and corrected in neonates. We advocate the radical surgical management, after exclusion of any primary malignant sites related to the gastrointestinal tract.