Patient diagnosed as squamous cell intraepithelial lesion which of the following has the highest risk for progression to carcinoma :

Ans. is b i.e. High grade squamous intraepithelial neoplasia There are various nomenclatures / classification systems for repoing of Pap smear. The one which is classically used is by WHO, which uses the terms CIN-I, CIN-II and CIN-III (as discussed in chapter on CIN). Another system is devised Bethesda. It classifies cytological abnormalities of premalignant leisons into three categories : Atypical squmous cells of undetermined signifcance (ASCUS). Low grade squamous intraepithelial lesion. High grade squamous intraepithelial lesion. Atypical Squamous Cells of Undetermined Significance : The most common cytologic abnormality is atypical squamous cells of undetermined significance (ASC-US). which indicates cells that are suggestive of, but do not fulfill the criteria for, SIL. The risk of progression to CIN-II or CIN-III approximates only 5% and cancer is found in only 1 to 2 per thousands instances. The evaluation of ASC-US should not be overly aggressive, paicularly in adolescents who are at low risk of cervical cancer. (American College of Obstetricians and Gynaecologists, 2006a: Moscicki, 2005). There are three options for evaluation of ASC-US - HPV DNA testing. Colposcopy. or Repeat cytologies at 6 and 12 months, with referral to colposcopy if either of these is abnormal. Low-Grade Squamous Intraepiethelial Lesion : This cytology result indicates the likely presence of HPV infection or low-grade neoplasia. Low-grade SIL encompasses the cytologic features of HPV infection and CIN-I and carries a 15 to 30 percent risk of progression to CIN-II or CIN-Ill. Therefore, colposocpy is indicated for most. High-Grade Squamous Intraepiethelial Lesion and Glandular Abnormalities : High grade SIL, should all be evaluated by prompt colposcopic evaluation. High-grade SIL cytology encompasses features of CIN-II and CIN-III and carries a high risk of underlying histologic CIN-II or CIN-Ill (at least 70%). or invasive cancer (1 to 2%). Alternative management of HSIL cytology in women age 21 years and older includes immediate diagnostic loop excision because colposcopy may miss a high-grade lesion and most HSIL cytologies evenatually result in excision for diagnosis or treatment.