Inflammatory carcinoma of the bladder and interstitial cystitis.

Two patients were treated for interstitial cystitis after having had bladder biopsies that did not reveal tumor. However, in both cases an aggressive carcinoma of the bladder later proved to be present when simple cystectomy for the "benign" disease was done. The masquerade of carcinoma of the bladder as interstitial cystitis and the pitfalls inherent in making the correct diagnosis are emphasized. The possibility of underlying bladder carcinoma should be excluded in any patient who presents with symptoms of chronic cystitis. Urinary cytology is most helpful but repeated bladder biopsy with careful serial sectioning may be necessary to establish the diagnosis of malignancy. It is not known whether the carcinomas were primary or secondary developments in our cases. The term inflammatory carcinoma of the bladder is proposed to call the attention of clinicians and pathologists to this lethal imitator.