Clinical Significance of Atypical Glandular Cells on Cervical Cytology

Abstract

To evaluate the prevalence and histologic outcomes of patients with atypical glandular cells of undetermined significance (AGUS), diagnosed by Pap test, and concurrent risk factors. A PubMed/MEDLINE/Ovid HealthStar search of the English literature was conducted from January 1988 through March 2004. The search criteria included the terms "atypical glandular cells of undetermined significance," "AGUS," or "AGC." All studies investigating the clinical significance of patients with an AGUS Pap test were included, except for those where consecutive Pap tests were not studied. Diagnostic outcomes were then determined. Of the 916 studies identified, 24 met our inclusion criteria. Of the 2,389,206 Pap tests included in these studies, 6,829 (0.29%) had AGUS. Follow-up was available for 3,890 tests. These data showed the following rates of pathology: 8.5% low-grade squamous intraepithelial lesions (LSIL), 11.1% high-grade squamous intraepithelial lesions (HSIL), 2.9% adenocarcinoma in situ, 1.4% endometrial hyperplasia, and 5.2% malignancy. The most common malignancies were endometrial adenocarcinoma (57.6%), cervical adenocarcinoma (23.6%), ovarian and fallopian tube carcinoma (6.4%), squamous cell carcinoma of the cervix (5.4%), and other (6.9%). Of the AGUS Pap tests, the remaining 71.0% corresponded to benign findings, including reactive changes, polyps, and normal histology. Patients with AGUS, which favors a neoplastic process, or with a concurrent ASCUS have a greater likelihood of disease. Histologic diagnosis showed that 29.0% of these Pap tests had findings requiring follow-up or therapeutic intervention, including a 5.2% rate of malignancy. Based on these findings, 99.6% of the diagnoses are within the region of surveillance when AGUS Pap tests are evaluated with colposcopy and directed biopsy, endocervical curettage, an endometrial biopsy in patients with risk factors for endometrial cancer, and pelvic examination.