Cytological diagnosis is a method of inspection for diagnosis of tumor benignancy or malignancy based on examination of tumor cells under a microscope. Initially, it was used to detect cancer cells, which naturally separate from vaginal secretions, phlegm, and urine. In recent years, however, there has been a change to a method of detecting cancer cells by active sampling of cells from morbid parts deep in the body using endoscopes or needles, and this procedure is winning widespread trust. The spread of cytological diagnosis is reflected in increased detection of uterine cancer in the "zero stage" (an early stage with a 100-percent rate of successful treatment). It is also contributing to early detection of other types of cancer.
In 1968, the schools were established for technical personnel needed for cytological diagnosis (clinical laboratory technologists) in two locations (the JFCR and the Osaka Medical Center for Cancer and Cardiovascular Diseases) in response to the requests of related societies and groups. Including the courses in the context of university education, there are currently five such schools nationwide. As of October 2005, the School of Cytotechnology had graduated a total of 532 students. This schooling is a system of practical education with close-knit person-to-person instruction limited to 10 - 15 students a year. Thus far, the Cancer Institute Hospital as a whole has graduated just under 2,200 cytoscreeners who are active on the front lines of the fight against cancer nationwide.
Japan had a total of 6,050 cytoscreeners in April 2001, and its cytological diagnosis technology ranks among the top worldwide.