NCI Dictionary of Cancer Terms The NCI Dictionary of Cancer Terms features 7,942 terms related to cancer and medicine. The search textbox has an autosuggest feature. When you enter three or more characters, a list of up to 10 suggestions will popup under the textbox. Use the arrow keys to move through the suggestions. To select a suggestion, hit the enter key. Using the escape key closes the listbox and puts you back at the textbox. The radio buttons allow you to toggle between having all search items start with or contain the text you entered in the search box. Starts with Contains Browse: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # dysplasia listen (dis-PLAY-zhuh) Cells that look abnormal under a microscope but are not cancer. Enlarge Normal cells may become cancer cells. Before cancer cells form in tissues of the body, the cells go through abnormal changes called hyperplasia and dysplasia. In hyperplasia, there is an increase in the number of cells in an organ or tissue that appear normal under a microscope. In dysplasia, the cells look abnormal under a microscope but are not cancer. Hyperplasia and dysplasia may or may not become cancer.