ASC-H A finding of abnormal cells in a Pap test. It means there are abnormal squamous cells in the tissue that lines the outer part of the cervix. ASC-H may be a sign of a high-grade squamous intraepithelial lesion (HSIL) , which may become cervical cancer if untreated. More testing may be needed. Also called atypical squamous cells, cannot exclude a high-grade lesion.