Morphology of human carcinogenesis

Carcinogenesis, the process by which normal cells become neoplastic, has be en extensively studied in tissue cultures and animal models. Screening and periodic examination of various organs with the use of modem technology pro vides the opportunity of directly studying human carcinogenesis. Following is the description of morphologic changes accompanying the stages of carcin ogenesis in the most common human tumors, the lung, breast, uterine cervix; colon/rectum, and urinary bladder.