Quality of the exo-endocervical sampling in the prevention of uterine cervix cancer

Cervical and vaginal cytology, Papanicolaou test (PAP), is the most effective test for screening of preneoplastic lesions, and cervical cancer prevention. Its sensitivity goes from 50 to 98%, according to different statistics, and this variation is related to the sampling procedure. A satisfactory smear should be taken from the transformation zone, the junction between endocervix and exocervix. According to Bethesda, metaplastic and/or endocervical cells should be observed under the microscope. The traditional PAP smear includes an exo-endocervical sampling using the Ayre spatula; however, only near 50% of the smears are representative of the transformation zone. In this case report, we present the case of a 40-year-old woman who had negative cytology in five consecutive annual PAP smears, none of which showed metaplastic or endocervical cells. A new sample evidenced a carcinoma in situ (HSIL: high-grade squamous intraepithelial lesion). We emphasize the importance of performing a correct exo-endocervical sampling to allow prompt detection of all premalignant lesions and to prevent cervical cancer, which still persists with high mortality worldwide.