Introduction: The gold standard for diagnosis and immediate therapy of bladder cancer is a transurethral resection (TURB) followed by histopathologic evaluation. The aim of this study was to assess the reliability of visual diagnosis by the operating urologist concerning dignity (malignant/benign) and staging compared to histopathologic evaluation. This is especially crucial since early mitomycin C instillation is based on the urologist's first impression.
Study design and methods: This prospective study included 311 cases of TURB from five German institutions. Surgeons were asked to estimate dignity of the neoplasm, tumor stage, and grade according to a standardized questionnaire.
Results: The subjective estimation/visual diagnosis of the operating urologist achieved a sensitivity with respect to identifying malignant tumors as such of 97%, while specificity was only 41%. Accordingly, the positive (PPV) and negative predictive values (NPV) were 76% and 88%, respectively. In general, muscle invasive cancer was predicted more often than confirmed by pathology (PPV 52%). However, whenever muscle invasive cancer was excluded by the urologist, this was confirmed by the pathologist in most the cases (NPV 95%). The educational degree did not influence the reliability and predictive value of visual diagnosis.
Conclusion: This study shows that urologists cannot reliably distinguish benign from malignant lesions of bladder mucosa-regardless of their educational degree. A reliable diagnosis of a pathologist is definitely needed to plan final therapeutic steps.