Natural history of the minimally abnormal Papanicolaou smear

We sought to determine the natural history of the cytologic and colposcopic changes in patients with minimal abnormalities on their Papanicolaou smears (atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion [SIL]).

Between November 1988 and November 1990, 632 women with abnormal Papanicolaou smears as listed above were evaluated at Los Angeles County-Olive View Medical Center. Each had review of cytology, repeat Papanicolaou smear, and colposcopy of the lower genital tract. We excluded those who were pregnant or had findings demonstrative of moderate dysplasia or worse, or had a cervical biopsy for any other indication. Women with symptomatic vaginal discharge were treated and remained in the study. Subjects were followed every 3 months with repeat Papanicolaou smear and colposcopy for a minimum of 9 months. If at any time the Papanicolaou smear or colposcopy was consistent with moderate dysplasia or worse, directed biopsies and endocervical curettage were performed, and treatment was given accordingly. Two hundred ninety-four patients fulfilled all inclusion criteria and had adequate follow-up data.

Nine months after enrollment, 42 of 91 women (46.2%) with atypical squamous cells had persistent changes, none had progression, and 49 (53.8%) had regression to normal. In those with low-grade SIL, 37 of 203 cases (18.2%) persisted, seven (3.4%) progressed, and 159 (78.3%) regressed by 9 months. Patients in the first group were more likely to have persistence of the cytologic abnormalities than were those in the second (P less than .01). Only the latter group progressed to high-grade dysplasia during the 9-month study interval.

The majority of women with confirmed minimal cytologic changes on Papanicolaou smear will have complete colposcopic and cytologic regression over a short interval.