title: A referral center's experience with transitional cell carcinoma misdiagnosed as interstitial cystitis.
abstract: OBJECTIVE
  There has been a recent trend to diagnose interstitial cystitis (IC) in a noninvasive way using a potassium sensitivity test, and a pelvic pain, urgency and frequency questionnaire. The concern is that significant pathology causing the bladder symptoms may be missed, such as transitional cell carcinoma. We present our experience with patients "labeled" as having IC who truly had cancer as the cause of irritative symptoms.
  
  
  METHODS
  A retrospective review of patient records at our IC center was performed from 1998 to 2002. A total of 600 patients were seen at that time with the diagnosis of interstitial cystitis.
  
  
  RESULTS
  Six patients (1%) previously diagnosed as having IC were found to have transitional cell carcinoma as the cause of symptoms, 4 of whom (67%) had no hematuria. Mean time from the diagnosis of IC to diagnosis of transitional cell carcinoma was 29.8 months. Irritative bladder symptoms resolved after identifying and treating the malignancy.
  
  
  CONCLUSIONS
  Patients with irritative voiding symptoms require a thorough evaluation which may include cystoscopy, cytology and upper tract imaging. Hematuria was not a good predictor of cancer in our series. In the era before widespread use of minimally invasive means to diagnose IC (ie potassium sensitivity test, pelvic pain, urgency and frequency questionnaire) 1% of patients who were considered to have IC actually had transitional cell cancer as the cause of symptoms. One would expect that this number would increase if the criteria to diagnose IC and initiate treatment were oversimplified. Interstitial cystitis remains a diagnosis of exclusion.
authors.affiliation: Department of Urology, William Beaumont Hospital, Royal Oak, Michigan, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Tissot
authors.forename: Ananias C
authors.initials: AC
authors.lastname: Diokno
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Peters
mesh_terms: D000328:Adult; D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis*; D018856:Cystitis, Interstitial / Q000175:diagnosis*; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012017:Referral and Consultation; D012189:Retrospective Studies; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis*