Cervical precancers have been classified in two ways i,e. Dysplasia /CIN
Mild dysplasia/ CIN I
Moderate dysplasia/ CIN II
Severe dysplasia/ CIN III
Depending upon the presence of atypical cells in different layers of squamous epithelium , the lesions are classified into CIN I, CIN II, CIN- III.
Atypical cells are characterized by-
-changes in nuclear cytoplasmic ratio
-increase in nuclear size
-loss of polarity
-increased mitotic figures
-hyperchromasia
CIN I – Presence of atypical cells in less than 1/3 of the thickness of epithelium
CIN II – Involvement of 1/3 to 2/3 of the thickness of epithelium by atypical cells
CIN III – Involvement of full thickness of the epithelium by atypical cells
Recent system or reporting of cervical neoplastic lesions in pap smears are by BETHESDA SYSTEM
ASCUS – Atypical squamous cells of unknown significance
LSIL -Low grade squamous intraepithelial lesion .
HSIL -High grade squamous intraepithelial lesion
Squamous cell carcinoma
LSIL may regress or only a small percentage of cases progress to HSIL
LSIL –high viral replication with mild alteration in the growth of the host cells
HSIL – low viral replication with increased cellular proliferation and dysregulation of cell cycle by HPV
The rates of progression are by no means uniform & although HPV type is potential predictor of lesion behavior.
This lesion may exist in the non-invasive stage for as long as 10 years & shed abnormal cells that can be detected on cytologic examination by Papanicolaou smear screening. Progression of lesion again depends upon the type of virus and immune status of individual
References
Vinay kumar, Abul K.Abbas, Nelson Fausto, Jon C. Aster. The Breast. In: Robbins and Cotran Pathologic basis of disease. 8th edition
