primary signetring cell carcinoma of the urinary bladder sixtyone cases of adenocarcinoma of the urinary bladder presenting between 1966 and 1981 were reviewed among the only seven cases of primary adenocarcinoma of the urinary bladder three were classified as primary signetring cell carcinoma these 3 cases were reviewed with the 11 previously reported cases in the literature primary signetring cell carcinoma of the urinary bladder occurs predominantly in men 12 men 2 women with age ranging from 38 to 83 years it usually runs a rapidly fatal course despite therapy the characteristic clinical gross and histomorphologic findings and pathogenesis of this rare bladder malignancy are discussed