MONDO_0004703 (bladder carcinoma in situ) is also known as carcinoma in situ of the urinary bladder or high grade intraurothelial neoplasia, this is a flat lesion of the transitional cell epithelium characterized by severe cytologic atypia. This lesion is confined to the urothelium, and is a precursor of invasive transitional cell carcinoma of the bladder. Stage 0is includes: Tis, N0, M0. Tis: Carcinoma in situ: "flat tumor". N0: No regional lymph node metastasis. M0: No distant metastasis. (AJCC 6th and 7th eds.). Also known as: bladder Ca in situ, bladder flat CIS, bladder flat carcinoma in situ, carcinoma in situ of bladder, carcinoma in situ of the urinary bladder, carcinoma in situ of urinary bladder, flat CIS of the bladder, flat CIS of the urinary bladder.