Bladder cancer. Light micrograph (LM) of a section of a bladder adenocarcinoma. Adenocarcinoma of the bladder is an uncommon malignant neoplasm and accounts for fewer than 2% of all malignant urinary bladder tumors. Urinary bladder adenocarcinoma begins in the cells of glandular structures lining body organs and spreads to the bladder. After treatment, patients must be monitored carefully because thechance of bladder cancer coming back is high-50 to 80 percent. In general, bladder cancers occur more often in men and in older adults. Magnification: x100 when printed at 10 centimetres wide. Human tissue.