Abstract
Intradiverticular bladder tumors (IDBT), rare at ∼1% of bladder cancers, present diagnostic difficulties due to absent muscularis propria, leading to frequent biopsy failures and staging errors. A 50-year-old man with gross hematuria had multiple negative cystoscopic biopsies, CT-guided biopsy, and cytology presented to oncology out patient. CT/PET-CT suggested an FDG-avid mass near the vesicoureteric junction, but MRI precisely located it in a diverticulum. Despite absent tissue diagnosis, partial cystectomy, diverticulectomy, distal ureterectomy, and psoas-hitch ureteric reimplantation were performed. Histopathology confirmed pTa high-grade papillary urothelial carcinoma. The patient is disease-free post-BCG highlighting that MRI-supported suspicion should prevail over negative histology in IDBT.