Should LSIL-H be a distinct cytology category? A study on the frequency and distribution of 40 human papillomavirus genotypes in 808 Women

BACKGROUND: The 2001 Bethesda System for gynecologic cervical cytology reporting classifies squamous intraepithelial lesions into low-grade (LSIL) and high-grade (HSIL) lesions. An intermediate term, "low-grade squamous intraepithelial lesion, cannot exclude high-grade squamous intraepithelial lesion (LSIL-H)," has been used in a small percentage of LSIL cases. To the authors' knowledge, little is known regarding the human papillomavirus (HPV) status in patients with LSIL-H. METHODS: A total of 808 SurePath specimens obtained between December 2009 and April 2011 were tested for 40 HPV genotypes using DNA microarray, followed by a confirmatory DNA sequencing assay. RESULTS: The infection rate for high-risk HPV in women with LSIL-H (92%) was strikingly close to that for women with HSIL (91%), which was higher than that for those with LSIL (74%); atypical squamous cells, cannot rule out high-grade lesion (ASC-H) (78%); or LSIL and ASC-H combined (74%). HPV type 16, the most common carcinogenic HPV genotype, was detected in 36% of women with LSIL-H, which was significantly higher than that in women with LSIL and ASC-H combined (13.8%), but less than that in women with HSIL (44.6%). Patients with LSIL-H and HSIL had similar infection rates for low-risk/intermediate-risk HPV genotypes, which were lower than those in LSIL or LSIL and ASC-H combined. CONCLUSIONS: Women found to have LSIL-H on a Papanicolaou test appear to have a unique HPV distribution pattern that clearly differs from LSIL and is comparable to that for HSIL, suggesting an increased risk of high-grade lesions over that of women with LSIL. Recognizing LSIL-H as an independent diagnostic category may help in the early identification of the high-risk subgroup that may require a management algorithm comparable to that for patients with HSIL.