Excluding confusable diseases in patients with presumptive diagnosis of interstitial cystitis: A large patient cohort study.

Objective: To analyze the results of excluding confusable diseases in patients with a presumptive diagnosis of interstitial cystitis (IC).

Methods: We retrospectively reviewed the electronic medical records of consecutive patients with IC between October 2005 and December 2019.

Results: Patients with pelvic pain underwent an initial workup. Of these, 646 patients (164 men, 25.4%; 482 women, 74.6%) underwent observational cystoscopy under the suspicion of IC. Fourteen patients had genitourinary tract malignancies (2.2%) (bladder cancer, n = 13; prostate cancer, n = 1). Of the 13 patients with bladder cancer, three were diagnosed during initial observation cystoscopy. The remaining 10 patients were diagnosed during subsequent follow-up cystoscopic surgery. Urinary tuberculosis was identified in seven (1.1%) of 646 patients during the examination. Five (0.8%) of the six patients with suspected urinary tuberculosis at baseline imaging were positive for tuberculosis in the acid-fast bacillus test. One patient developed tuberculous granulomas in the bladder tissue after a cystectomy for intractable pelvic pain.

Conclusion: Our results show that continuous efforts to rule out bladder tumors or tuberculosis are still essential in the follow up of patients with suspected IC, even if these diseases are not excluded at the initial examination. Imaging studies are necessary to rule out tuberculosis.