Laryngeal papillomatosis associated dysplasia in the adult population: an update on prevalence and HPV subtyping.

OBJECTIVES The objectives were to determine the prevalence of laryngeal dysplasia and associated human papilloma virus (HPV) subtypes in adult patients, 18 years or older, suffering from laryngeal papillomatosis at a tertiary care institution. STUDY DESIGN Retrospective cohort study. METHODS Patients with biopsy proven laryngeal papillomatosis were identified via chart review. All available pathology specimens were reviewed by a dedicated head and neck pathologist to confirm/refute the diagnosis of laryngeal dysplasia, and grade the level of dysplasia. Interrater agreement was compared using cross-tabulation methods. Specimens identified to be positive for dysplasia underwent further testing via in situ hybridization for low-risk (6/11) or high-risk (16/18) HPV subtypes. RESULTS Of the 85 subjects identified to have laryngeal papillomatosis, 24(28%) demonstrated laryngeal dysplasia. There was good interrater agreement on the presence of dysplasia; however, there was only fair agreement on the grade of dysplasia. Of the pathology specimens tested for HPV subtype, the majority of patients (62%) were positive for HPV 6/11, including all high-grade dysplasia patients. Three (12%) dysplasia specimens were negative for both high- and low-risk HPV subtypes. CONCLUSIONS We found a 28% prevalence of dysplasia in our patient population with the majority of patients positive for low-risk HPV subtypes indicating that high-risk HPV subtypes do not predispose laryngeal papilloma patients to dysplasia.