Clinical significance of atypical glandular cells of undetermined significance. A follow-up study from an academic medical center

OBJECTIVE: To determine the rate of atypical glandular cells of undetermined significance (AGUS) and the incidence of subsequent clinically significant lesions. STUDY DESIGN: A computer-based search of our cytology laboratory files was performed for cervicovaginal smears diagnosed as AGUS from January 1996 to December 1996. RESULTS: In 43,456 cervicovaginal smears examined during the 12-month period, AGUS was reported in 222 (0.5%) cases, with follow-up in 191 (86.0%) (133 [59.9%] biopsies and 58 [26.1%] repeat cervicovaginal smears). Among the patients with repeat cervicovaginal smears, 1 (1.7%) had a high grade squamous intraepithelial lesion, and 10 (17.2%) had persistent AGUS/atypical squamous cells of undetermined significance; the remainder were within normal limits. Thirty-three (24.8%) patients had preneoplastic or neoplastic, squamous or glandular lesions on biopsy (8 [6.0%] cervical intraepithelial neoplasia [CIN] 1, 18 [13.5%] CIN 2/3 and 7 [5.3%] endometrial adenocarcinomas). Half the patients with CIN 2/3 also had evidence of endocervical gland involvement. Squamous lesions were seen more commonly in premenopausal women, while glandular lesions were noted predominantly in postmenopausal women. Patients with a prior abnormal gynecologic history or a concomitant diagnosis of squamous intraepithelial lesion (SIL) had a higher incidence of significant lesions on subsequent biopsy. CONCLUSION: Our incidence of AGUS was 0.5%, similar to that in other published reports. AGUS is associated with a significant number of squamous or glandular, premalignant or malignant lesions. A majority of these lesions are high grade SIL, often with endocervical gland involvement. A small but significant number of patients had a glandular malignancy. Our results justify close and persistent follow-up for patients with a diagnosis of AGUS on cervicovaginal smears.