NCI Dictionary of Cancer Terms

The NCI Dictionary of Cancer Terms features 8,573 terms related to cancer and medicine.

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high-grade squamous intraepithelial lesion
(... SKWAY-mus IN-truh-eh-pih-THEE-lee-ul LEE-zhun)
An area of abnormal cells that forms on the surface of certain organs, such as the cervix, vagina, vulva, anus, and esophagus. High-grade squamous intraepithelial lesions look somewhat to very abnormal when looked at under a microscope. They are usually caused by chronic infection with certain types of human papillomavirus (HPV) and are found when a Pap test or biopsy are done. If not treated, these abnormal cells may become cancer and spread to nearby normal tissue. A high-grade squamous intraepithelial lesion is sometimes called moderate or severe dysplasia. Also called HSIL.