Urinary bladder adenocarcinoma is an uncommon disease. The histological diagnosis of bladder adenocarcinoma is usually straightforward. However, bladder carcinoma rarely shows benign-mimicking features. We report on a 64-year-old woman who was diagnosed with urinary bladder adenocarcinoma, which was well differentiated with the features of minimal deviation adenocarcinoma. Most of the tumor cells were slightly atypical, and the tumor was differentiated barely from the benign disease. Careful examination was necessary for a correct diagnosis. The pathology comprised invasive foci with desmoplastic reaction in the extravesicular adipose tissue.