Objective: This study was undertaken to evaluate the topographic distribution of precancerous intraepithelial lesions on the cervix.
Study design: We studied the distribution of cervical biopsies and location of acetowhite lesions as determined by cervigrams among women who underwent a colposcopic examination and biopsy during the ASCUS-LSIL Triage Study (ALTS).
Results: More biopsies were taken in the 12 o'clock (41.4%) and 6 o'clock (28.4%) quadrants than in 3 o'clock and 9 o'clock quadrant (15.8% and 14.5%, respectively) (P<.001). The proportion of abnormal histology per biopsy, and the grade of neoplasia, did not vary significantly by position. Cervigrams demonstrated visible intraepithelial lesions and acetowhitening more common on the anterior and posterior quadrants of the cervix.
Conclusion: More cervical intraepithelial neoplasia might develop at the anterior and posterior lips of the cervix. However, the evidence is weak and confounded by a tendency of the anterior and posterior quadrants to be acetowhite even in the absence of cervical intraepithelial neoplasia.