1. Normal urothelium Cell layers Urothelium = all epithelial cells • Superficial/umbrella • Intermediate • 2 to >10 cells • Basal

2. Normal urothelial mucosa Mucosa = Urothelium + stroma beneath urothelium deep to muscularis mucosae

3. Normal urothelial mucosa

4. Normal urothelial mucosa Brunn’s nests Urothelium Mucosa Muscularis mucosae

5. Normal urothelial mucosa Urothelium Cystitis cystica Mucosa Muscularis mucosae

6. Muscularis mucosae Urothelium Lamina propria Mucosa Submucosa Lymphoid nodule Muscularis propria

7. Muscularis mucosae Distribution of muscularis mucosae (as % of bladders) Prominent & continuous 3 % Discontinuous & interrupted 20 % Scattered & dispersed 71 % Absent 6 % Muscularis propria

8. Pathologic staging of bladder tumors Ta and Tis tumors T1 tumors T2 tumors