Carcinoma in situ of the urinary bladder. Clinical presentation, cytologic pattern and stromal changes.

The clinical presentation, cytologic pattern and stromal changes in the cystectomy specimen were studied in a group of 26 patients with carcinoma in situ of the urinary bladder who underwent cystectomy. Only cases in which the nuclear area of the carcinoma in situ cells was over 80 sq micron (large-cell type) were included in this study. The results indicate that the cells from large-cell carcinoma in situ of the bladder exfoliate easily, resulting in a cytologic pattern of predominantly single, highly abnormal cancer cells. Due to the increased exfoliation of the affected epithelium, the bladder stroma is focally denuded; therefore, while cytology may be strongly positive for malignancy in these cases, the histologic diagnosis can be falsely negative when only denuded stroma is biopsied. The edematous stroma causes complaints of "cystitis." The neoplastic urothelium may involve contiguously related epithelial surfaces. When the lesion extends into the prostatic ducts, the patient can have "pseudoprostatitis" complaints. Urethral extension may give penile voiding pain. In one female patient, involvement of the vagina and vulva was found. Carcinoma in situ may develop in patients with papillary low-grade bladder carcinoma during follow-up, with a concomitant shift in the cytologic and clinical patterns; this deserves the consideration and attention of the cytologist and the clinician due to its serious clinical implications.