This patient, with history of Thiotepa therapy, presented with gross hematuria and was found to have erythematous areas on cystoscopy. The biopsy shows considerable cytologic atypia in the superficial layers of the urothelium. The nuclei are enlarged, hyperchromatic and irregular. A few acute inflammatory cells are also present. The prior history of therapy with agents such as Thiotepa raises the threshold for labeling such cases as dysplasia/CIS.