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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 is done. If not treated, these abnormal cells may become cancer and spread into nearby tissue. A high-grade squamous intraepithelial lesion is sometimes called moderate or severe dysplasia. Also called HSIL.
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Cervical changes; drawing shows a cross-section of the uterus, cervix, and vagina. Also shown are four panels showing cell changes inside the cervix. The first panel shows normal cells. The second and third panels show abnormal cells called LSIL and HSIL. The fourth panel shows cervical cancer cells. Arrows are used between the panels to show that normal cells may become LSIL or HSIL, which may or may not become cancer.Enlarge this image in new window
Cervical changes. The cervix is the lower, narrow end of the uterus that forms a canal between the uterus and vagina. Before cancer cells form in tissues of the cervix, the cells of the cervix go through abnormal changes called dysplasia. There are different types of dysplasia. Mild dysplasia, called low-grade intraepithelial lesion (LSIL) is one type. Moderate or severe dysplasia, called high-grade intraepithelial lesion (HSIL) is another type of dysplasia. LSIL and HSIL may or may not become cancer.
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