The signet-ring cell carcinoma of the urinary bladder as a rare histopathological variant of the adenocarcinoma is demonstrated with the help of clinical, cytological and histological findings of a case (29-year-old male) and it is referred to etiopathogenetic as well as clinical particularities which render possible a delimitation from the carcinoma of the epithelium of the urinary tract. Half of all 28 cases published up to now issued from the remaining parts of the urachus, particularly when localized in the parietal region. The from the first deeply infiltrating growth in the wall of the urinary bladder demands larger surgical interventions, in which cases the partial resection of the urinary bladder represents still the most insignificant operative procedure with clearly better prognosis. For improving the therapeutic situation and the dubious prognosis urachus carriers should be operated on in time, whereby for their recognition modern picture-producing diagnostic method such as sonography should be utilized.