Contribution of the endocervical Cytobrush sample to the diagnosis of cervical lesions

To compare the contribution of endocervical Cytobrush samples to wooden spatula samples in the detection of cervical preneoplastic lesions.

Cytobrush sampling was performed on 56,120 women in conjunction with ectocervical spatula sampling, resulting in two smears per patient. Almost all women with cytologic diagnoses of high grade squamous intraepithelial lesions (CIN 3) or higher were biopsied.

For the 221 CIN 3, the contribution of the endocervical sample was clearly more efficient, with diagnosis achieved on 98% of the endocervical samples and on 62% of the ectocervical ones. In the 674 low grade squamous epithelial lesion cases, the endocervical samples were diagnostic in 79% of cases and the ectocervical smears in 64%. Thus, endocervical sampling proved to be superior in the recognition of precancerous lesions. In 93% of the 53 squamous carcinomas, cancer cells were found in both ectocervical and endocervical samples and in 7%, exclusively in endocervical smears. In 76% of the 21 adenocarcinomas, both samples were positive, and in 23% only the endocervical sample contained cancer cells.

The Cytobrush samples were more efficient in the detection of intraepithelial neoplastic lesions, suggesting that most of them originate in the endocervical epithelium. If the sampling were limited to endocervical brushing, 14% of cervical lesions would not have been detected in the smear. The prominence of preneoplastic cells in the endocervical samples might indicate that the original glandular epithelium is the major site of cervical carcinogenesis.