Diagnostic Ureteroscopy for Cases Clinically Suspected of Carcinoma in Situ of the Upper Urinary Tract
U rothelial carcinoma of the upper urinary tract (UTUC) is uncommon, accounting for less than 5% of all urothelial carcinomas (UCs)   . Standard diagnostic methods for UTUC include upper-tract imaging (CT urography [CTU] is the first-line) and urine cytology  . The detection rate of UTUC is satisfactory with high specificity for CT urography in parallel with the development of CT devices  . Current indications for nephro-ureterectomy with ipsilateral bladder cuff excision include
... excision include cases of suspected UTUC based on imaging and positive urine cytology. However, there are minor cases with consistently positive urine cytology that show poorly detectable lesions in the upper urinary tract, i.e., filling defects and/or wall thickness, on imaging studies. Such cases in whom lower urinary tract malignancy has been excluded are suspected of flat UTUC or carcinoma in situ of the upper tract (UT-Cis). However, there is poor evidence of efficient diagnostic options for such cases. Ureteroscopy (URS) for the upper urinary tract was previously a relatively invasive work-up with common adverse effects. Recently, small-diameter, flexible, high-resolution ureteroscopes have enabled safe access http ://escholarship.lib.okayama-u.ac.jp/amo/ Original Article We elucidate the fate of cases clinically suspected of carcinoma in situ (Cis) of the upper tract with serial ureteroscopy. Of 143 patients who underwent ureteroscopy for suspected upper tract urothelial carcinoma (UTUC) between January 2008 and February 2016, 12 cases with consistently positive urine cytology and poorly detectable upper-tract malignancies by imaging were reviewed. In these 12 patients, 19 ureteroscopy procedures (25 renal units) were performed. Vesical random biopsy was performed before the 1st ureteroscopy to exclude malignancy of the bladder in all 12 cases. Median follow-up was 42 (13-67) months. Positive biopsy results at the 1st ureteroscopy were obtained in 3 (25%) patients and all were diagnosed wth Cis of the upper tract. Two (17%) of 9 patients who were negative or inconclusive at the 1st ureteroscopy were finally diagnosed as UTUC, but plural ureteroscopy procedures were needed for the diagnoses in both. Carcinoma of the bladder appeared in 5 (42%) patients during follow-up, despite the earlier ruling out of vesical malignancy. Four (33%) of those 5 patients never developed upper-tract urothelial carcinoma during follow-up. Caution is required before undertaking radical surgery for cases clinically suspected of Cis of the upper tract. In our experience, only 42% of such patients developed UTUC; another 33% eventually developed carcinoma of the bladder without UTUC.