Malignant transformation in non-irradiated juvenile laryngeal papillomatosis.

A spontaneous cancer transformation of non-irradiated juvenile papillomas has been observed in a very small number of cases. We report on six more patients with juvenile laryngeal papillomatosis developing into a squamous-cell carcinoma. Three patients had childhood papillomatosis and three patients adult onsets of their papillomas. The average duration between onset of papillomatosis and cancer diagnosis was 33 years, while the average age at time of diagnosis of a laryngeal cancer was 50 years. All patients were cigarette smokers, but none of them had received prior irradiation. The typical histological picture of tumors showed an infiltrating keratinizing squamous carcinoma besides remaining benign papillomas within the larynx. Our study again illustrates the risk of malignant transformation of juvenile papillomatosis in long-lasting cases. Therefore, regular extensive biopsies and careful histopathological examination are required. The role of smoking as a co-factor in the development of carcinoma ex-papilloma is still not clear.