• | Denudation and ulceration of urothelium |
• | Non-caseating granulomas |
• | Reactive epithelial atypia |
• | Degenerated urothelial cells and extensive background debris with histiocytes and rare multinucleated giant cells on cytological examination |
• | Lamina propria oedema (interferon α) |
• | Mild perivascular inflammation with lymphocytes, eosinophils, plasma cells, and dendritic cells (interferon α) |
• | Persistence of carcinoma in situ (in von Brunn's nests) |