<prompt> Patient diagnosed as squamous cell intraepithelial lesion which of the following has the highest risk for progression to carcinoma:Low grade squamous intraepithelial neoplasiaHigh grade squamous intraepithelial neoplasiaSquamous intraepithelial associated with HPV 16Squamous intraepithelial neoplasia associated with HIV  <response>: Ans. is b, i.e. High grade squamous intraepithelial neoplasiaRef: Shaw 15thed, p402; Williams Gynae 1sted, p629There are various nomenclaturesclassification systems for reporting of Pap smear.The one which is classically used is by WHO, which uses the terms CIN-I, CIN-II and CIN-IIIAnother system as discussed earlier is Bethesda which classified the disease as LSILlow grade squamous intraepithelial lesion and HSIL high grade squamous intraepithelial lesion and chances of progressing to cancer are maximum with HSIL which includes CIN11, CIN111 and ca in situ. 