bladder carcinoma in situ
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.)