Significance of a diagnosis of atypical squamous cells of undetermined significance for Papanicolaou smears in perimenopausal and postmenopausal women

BACKGROUND. The current study was conducted to determine the significance of a diagnosis of atypical squamous cells of undetermined significance (ASCUS) in perimenopausal and postmenopausal women. METHODS, The reports for all Papanicolaou (Pap) smears viewed in the study institution's cytology laboratory over a B-month period were reviewed. Women were divided into premenopausal (age less than or equal to 45 years), perimenopausal (ages 46-54 years), and postmenopausal (age greater than or equal to 55 years) categories. Slide review and 2-year follow-up were obtained for selected cases diagnosed as ASCUS. ASCUS cases among the perimenopausal women were compared with an age-matched control group. RESULTS. The total number of abnormal Pap smears in the premenopausal, perimenopausal, and postmenopausal categories were 770 (6.8%), 104 (4.3%), and 67 (2.9%), with 482, 83, and 41 diagnoses of ASCUS, respectively. The ratio of ASCUS to squamous intraepithelial lesions (SIL) was 2.2 overall and 1.9, 7.5, and 4.1, respectively, for each group (P < 0.001). The positive predictive value for a diagnosis of SIL on subsequent Pap smears or biopsies was 22%, 12.2%, and 29.7%, respectively. Slide review showed that the premenopausal ASCUS cases appeared to have a higher percentage of nuclear-cytoplasmic ratio increase and nuclear membrane irregularities compared with the other categories (P = 0.03 and P = 0.02, respectively) and the perimenopausal group was found to have more ASCUS in metaplastic cells (P = 0.03). In perimenopausal women, slides diagnosed as ASCUS demonstrated more air-drying artifact than the control group (P = 0.004) but had less obvious atrophy (P = 0.01). CONCLUSIONS. Despite a decreased abnormality rate with increasing age, the results of the current study show that the perimenopausal and postmenopausal groups appear to have elevated ASCUS-to-SIL ratios. ASCUS appears to have a particularly low positive predictive value for SIL in perimenopausal women, and therefore most likely is overcalled in this age group. This may be attributable in part to air-drying artifact and subtle atrophic changes. Cancer (Cancer Cytopathol) 2001;93:100-105. (C) 2001 American Cancer Society.