[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. — 2003 ( NCI )]
UMLS (NCI) C0154091