Connective tissue stroma in bladder papillary transitional cell carcinoma, carcinoma in situ and benign cystitis.

The stromal characteristics in papillary and non-papillary tumours of the urinary bladder were investigated in an attempt to improve the accuracy of histopathological diagnosis. It appeared to be possible to differentiate true papillary tumours from pseudopapillary structures lined by carcinoma in situ. Stromal differences were not found in cases of carcinoma in situ accompanied by denuding cystitis and cystitis due to other aetiological factors. It is concluded that histopathological examination of the stroma of bladder tumours improves diagnostic accuracy.