This term means there are abnormal cells in the lining of the back passage (anus). It is also called anal squamous intraepithelial lesions (SILs). AIN is not cancer but the cells might develop into cancer in the future. This is diagnosed by taking a sample of skin (biopsy) to be examined under a microscope. It… Continue reading Anal Intraepithelial Neoplasia (AIN)