Ketamine cystitis as a mimic of carcinoma in situ.

AIMS: To describe the histopathological features of a series of patients with ketamine-related cystitis.

METHODS AND

RESULTS

Seventeen patients with ketamine-related cystitis, who had undergone biopsy, were identified and reviewed. Twelve showed ulceration with significant urothelial atypia. In 10 of these, immunohistochemistry was performed; 9/10 had high p53 immunoreactivity and 7/10 had moderate to high levels of Ki67 reactivity, but all were negative for cytokeratin 20.

CONCLUSIONS

Ketamine can lead to reactive urothelial changes that can mimic carcinoma in situ, but the long-term cancer risk remains unknown.