A high-grade squamous intraepithelial lesion, also called HSIL or HGSIL, is an abnormal growth of cells on the cervix. These cells are found in a Pap smear. The presence of HSIL is often linked to cervical cancer. The diagnosis of a high-grade squamous intraepithelial lesion usually indicates the need for further testing to asses the potential cancer risk. A Pap smear is part of a gynecological pelvic examination where the doctor scrapes a small amount of tissue off the surface of the cervix. The cells are examined under a microscope in a laboratory, where a technician looks at the size and shape of the cells. A diagnosis of a low-grade squamous intraepithelial lesion, or LSIL indicates that there is a small amount of abnormal cells and that not much of the cervix is affected. A high-grade squamous intraepithelial lesion indicates a large number of very abnormal cells covering much of the cervix.