The predictive value of human papilloma virus (HPV) typing in the prognosis of bronchial squamous cell papillomas.

Five solitary squamous papillomas of bronchus with variable degrees of dysplasia, one combined with a laryngeal papilloma and with a neuroendocrine carcinoma in the contralateral lung, and five papillomas combined with invasive squamous cell carcinomas were investigated for their expression of human papilloma virus DNA by in situ hybridization. Benign squamous cell papillomas showed an association with papilloma virus type 11 and rarely type 6, whereas types 16 or 18, sometimes in combination with types 31/33/35 were found in papillomas associated with carcinomas. In one patient a benign papilloma containing human papilloma virus type 18 and 31/33/35-positive preceded a recurrence combined with carcinoma by 2 years; this recurrent papilloma and the carcinoma were also positive for human papilloma virus 18 DNA. We suggest that human papilloma virus typing should be performed in every squamous cell papilloma of bronchus. Patients with papillomas exhibiting human papilloma virus 16 or 18 positivity are at high risk for the development of squamous cell carcinoma. Furthermore, virus typing may be of prognostic importance in relation to the development of squamous carcinoma.