Trouble-makers in cytologic interpretation of the uterine cervix.

The development and standardization of cytologic screening of the uterine cervix has dramatically decreased the prevalence of squamous cell carcinoma of the uterine cervix. Advances in the understanding of biology of human papillomavirus have contributed to upgrading the histologic diagnosis of the uterine cervix; however, cytologic screening that should triage those that need further management still poses several difficulties in interpretation. Cytologic features of high grade intraepithelial squamous lesion (HSIL) mimics including atrophy, immature metaplasia, and transitional metaplasia, and glandular lesion masquerades including tubal metaplasia and HSIL with glandular involvement are described with accentuation mainly on the differential points. When the cytologic features lie in a gray zone between the differentials, the most important key to the more accurate interpretation is sticking to the very basics of cytology; screening the background and cellular architecture, and then scrutinizing the nuclear and cytoplasmic details.