“…The differential diagnosis of increasing debris or thickening within the diverticulum includes infection and inflammatory change within the UD and biopsies may yield no evidence of malignancy as in 2/3 of our UDC cases. Cystoscopy was unhelpful in our cases but may play an important role in the pathological diagnosis and in localization of the tumor origin ( 1 ) with neoplasm in the diverticulum or urethra noted on cystoscopy in 23/29 (79%) cases in those series reporting its use ( 7 , 9 , 10 , 12 , 21 , 23 , 31 , 42 , 53 , 54 , 57 , 72 , 73 , 77 , 96 , 98 , 100 ).…”