Distribution of cervical intraepithelial neoplasia across the cervix is random.Lurie S, Eliaz M, Boaz M, Levy T, Golan A, Sadan O. Am J Obstet Gynecol. 2007 Feb;196(2):125.e1-3.
High grade intraepithelial neoplasia is randomly distributed across the cervix. The authors state that location should not matter when deciding to perform a biopsy of lesions with abnormal colposcopic features.

Cytological status and lesion size: a further dimension in cervical intraepithelial neoplasia.Jarmulowicz MR, Jenkins D, Barton SE, Goodall AL, Hollingworth A, Singer A. Br J Obstet Gynaecol. 1989 Sep;96(9):1061-6.
Small lesions are more difficult to sample and lead to a higher misdiagnosis. Sampling error is more likely. Larger lesions are associated with CIN 3 and are less prone to cytological sampling error.

Switch from cytology-based to human papillomavirus test-based cervical screening: implications for colposcopy.Porras C, Wentzensen N, Rodríguez AC, Morales J, Burk RD, Alfaro M, Hutchinson M, Herrero R, Hildesheim A, Sherman ME, Wacholder S, Solomon D, Schiffman M. Int J Cancer. 2012 Apr 15;130(8):1879-87. doi: 10.1002/ijc.26194. Epub 2011 Aug 2.
Converting from cytological screening to HPV screening is not practical because of the limitations of colposcopy in follow up. There will be more positive screening tests, with limitations in visualizing CIN2+ lesions under conventional colposcopy. The authors conclude we need to seek non visual diagnostic confirmatory tests for the presence of high grade CIN.

Colposcopy prediction of progression in human papillomavirus infections with minor cervical lesions.del Pino M, Torne A, Alonso I, Mula R, Masoller N, Fuste V, Ordi J. Obstet Gynecol. 2010 Dec;116(6):1324-31.
Initial colposcopic lesion size or colposcopic grading did not predict which patients who were followed conservatively, would undergo progression of their lesion/disease. During follow-up, worsening of the colposcopic pattern did predict progression, however.