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.