Atypical glandular cells of undetermined significance. Histologic findings and proposed management.

OBJECTIVE To increase understanding of the clinical significance of atypical glandular cells of undetermined significance (AGUS) on cervical cytology and to suggest a management plan. STUDY DESIGN All Pap smears classified as AGUS over a period of five years at the University of Michigan Medical Center were reviewed and the diagnosis confirmed. The charts of these patients were reviewed for demographics, significant previous medical history, symptoms, diagnostic studies performed and final histologic diagnoses. RESULTS In 1993-1998, a total of 208,041 Pap smears were read. Two hundred seven smears from 189 patients were classified as AGUS, for an incidence of 0.1%. There were 136 patients with follow-up information and 114 patients with histologic diagnoses. In 55 of the 114 patients (48%), significant histologic abnormalities were observed, including 11 endometrial cancers, 1 invasive adenocarcinoma of the cervix, 3 adenocarcinomas in situ of the cervix, 18 CIN 3 lesions and 5 CIN 2 lesions. Among 20 patients with Pap smears subclassified as "atypical glandular cells of undetermined significance, favor benign process," there were two CIN 2, five CIN 3 and one adenocarcinoma in situ of the cervix. CONCLUSION A diagnosis of AGUS requires an aggressive workup because of the high rate of cancer and precancerous lesions. The evaluation, at the very least, should include colposcopy with directed biopsies and endocervical curettage. Postmenopausal patients, those with irregular bleeding and those with high risk characteristics should also undergo endometrial biopsy.