Abstract
BACKGROUND: An ileal neobladder is a standardized form of urinary diversion that provides acceptable outcomes in terms of long-term quality of life. Urothelial carcinomas (UCs) arising in the ileal neobladder are extremely rare, and few reports on this have been published in the English language. CASE SUMMARY: We report a case of UC that developed in the ileal neobladder of a 63-year-old man. The patient was diagnosed with UC in situ and underwent radical cystoprostatectomy and ileal neobladder creation. Ten years after the surgery and neoadjuvant chemotherapy, an UC developed in the ileal neobladder. CONCLUSION: Ileal neobladder urothelial carcinoma can originate from the implanted urothelium and the intestinal mucosa can migrate intraluminally.