Flat intra-epithelial carcinoma in situ of the urinary bladder

A follow-up investigation of 19 patients with carcinoma in situ per se of the urinary bladder (Tis) has been performed. Ten patients developed invasive cancer during a mean observation period of about 4 years. The natural history is unpredictable and therapeutic management of this potentially malignant neoplasm should be individualised. Early radical cystectomy is advocated in selected cases of Tis.