Bladder cancer is one of the most common cancers in global statistics. One of the issues associated with this disease is the high incidence of cases with delayed diagnosis and what factors correlate with worse treatment outcomes. A possible reason for this may be the rather limited availability of non-invasive diagnostic tools. This short communication presents a case of a 68 year old male patient after an ineffective therapy, carried on for several years with symptoms commonly associated with prostate overgrowth that masked a carcinoma in situ of the urinary bladder. Implementation of several diagnostic techniques, including urine sediment cytology, immunocytochemistry, the fluorescence in situ hybridisation technique, the Bladder EpiCheck test and whole-genome sequencing, enabled the establishment of a correct diagnosis, implementation of appropriate treatment and provision of patient-friendly monitoring. The described case emphasises the usefulness of cell-based and liquid-based urine tests in bladder cancer diagnostic procedures.