Intermediate-grade squamous intraepithelial lesion may be a valid diagnostic/interpretive category.

We undertook this study to assess the characteristics of smears with features intermediate between high-grade squamous intraepithelial lesion (HSIL) and low-grade squamous intraepithelial lesion (ISIL). We also wanted to determine how these smears correlate with high risk biopsy diagnosis and to compare this with the biopsy correlation of LSIL and HSIL. Seventy-four squamous intraepithelial lesion (SIL) smears were identified as intermediate-grade SIL smears taken at colposcopy in a 1 year period. They were correlated with concurrent colposcopically guided biopsies. Thirty-five percent of cases with intermediate-grade SIL smears had a biopsy diagnosis of moderate dysplasia or higher as compared with 12% for LSIL 74% for HSIL. This confirmed our hypothesis that intermediate-grade SIL smears have a rate of biopsy diagnosis of moderate dysplasia or higher intermediate to that of LSIL and HSIL.