Flat Tumors (Carcinoma in Situ, CIS): These do not grow into the bladder’s hollow part and are confined to the inner layer.
Papillary Tumors: These grow in thin, finger-like projections toward the bladder’s center. They are further categorized into:
- PUNLMP (Papillary Urothelial Neoplasm of Low-Malignant Potential): Very low-grade tumors that rarely become invasive but can recur.
- LGPUC (Non-Invasive Low-Grade Papillary Urothelial Carcinoma): Slightly more abnormal-looking cells that might come back after treatment.
- HGPUC (Non-Invasive High-Grade Papillary Urothelial Carcinoma): These have highly abnormal cells and are at higher risk of becoming invasive or indicating nearby invasive cancer.
If these tumors grow into deeper bladder layers, they are considered invasive urothelial carcinoma.