Inaccuracy of Ureteroscopic Biopsy in Upper Tract Urothelial Carcinoma Can Lead to False Therapeutic Decisions: A Case Report

Do not rely solely on negative endoscopic biopsies when diagnosing upper tract urothelial carcinoma (UTUC). Repeat ureteroscopy with biopsy if initial results are negative to reduce false negatives. Frozen section analysis (FSA) can provide rapid intraoperative confirmation and guide treatment decisions. Emerging tools such as fluorescence confocal microscopy may improve diagnostic accuracy and warrant further study.