What is the role of a pathologist in a cancer diagnosis?

Cancer is diagnosed and classified by the examination of tissue or individual cells obtained by various methods. Using a microscope and other special tests, pathologists are specially trained to recognize many tumor types, and to help predict a patient's prognosis by giving the stage (size and extent) and grade (level of aggressiveness) of their tumor. Pathologists are also trained to help surgeons determine whether a tumor has been completely removed. Additionally, pathologists perform a growing array of special molecular and genetic tests to assess prognosis in certain tumor types.  more