Background: A rare report of a tubulovillous adenoma arising in the setting of a dual pancreas-kidney transplant patient. Case Presentation: This adenoma was discovered in a 60-year-old male with a dual pancreas-kidney transplant that presented with urinary retention and gross hematuria. Management of this patient required both transurethral resection of the tumor as well as a laparotomy after recurrence. Follow-up with cystoscopy has shown no further recurrence of the tumor. Conclusion: This case adds to the few cases documented of adenomas arising in bladders augmented with gastrointestinal tract tissue. The tumor may reflect growth from donor duodenal graft tissue, however, the metaplasia of urothelial tissue cannot be fully ruled out. Based on this case, our understanding of these rare tumors and their clinical course is deepened.