Squamous intraepithelial lesions of the cervix in a high-risk population

We set out to examine our use of the squamous intraepithelial lesion (SIL) category, compare our SIL rate to rates reported by others, and determine the corre-lation between SIL and histologically proven cervical intraepithelial neoplasia (CIN) in our population.

Reports from all Papanicolaou smears and associated histological specimens interpreted by the University of Florida Department of Pathology between 1992 and 1996 were reviewed.

Of 39,484 Papanicolaou smears, 2,101 (5.3%) were classified as low-grade squamous intraepithelial lesion (LGSIL) and 1,366 (3.5%) were classified as high-grade (HGSIL). Of the LGSIL cases, 972 (46.3%) underwent timely biopsy: Findings were benign in 29.9%; 41.7% had CIN1,20.9% had CIN2, and 7.5% had CIN3. Of the HGSIL cases, 932 (68.2%) underwent timely biopsy: Findings were benign in 12.3%; 17.1% had CIN1, 26.7% had CIN2, 42.2% had CIN3, and 1.6% showed squamous cell carcinoma. Condusions. Our LGSIL rate is similar to reported rates, but our HGSIL rate of 3.5% is higher. We found good correlation between SIL on Papanicolaou smear and CIN on biopsy (70.1% for LGSIL and 86% for HGSIL).