anal epithelial dysplasia

See : anal intraepithelial neoplasia (AIN )

Stage 0 – anal intraepithelial neoplasia / anal carcinoma in situ (AIN )

There are different grades of AIN :

 AIN1 means the abnormal cells are in the lower one third of the skin covering the anus
 AIN2 means the abnormal cells are in the lower two thirds of the skin
 AIN3 means the abnormal cells are in the full thickness of the skin of the anus