[Virologic aspects of juvenile laryngeal papillomatosis]

Juvenile laryngeal papillomatosis is the most common benign tumor of the larynx in childhood. The specific etiological factors are non-oncogenic human papillomavirus types 6 and 11. In the present study two cases (a 6-year-old male and a 5 and a half-year-old female) operated five times each and harbouring type 11 DNA in papillomas excised in the first operations are analysed from the following virological aspects: 1. the examination of vertical transmission by general primer-polymerase chain reaction of maternal cervical exfoliation; 2. sites of papilloma predilections in the larynx; 3. histopathology; 4. viral DNA detection from the formalin-fixed and paraffin-embedded archive tissues and from a fresh papilloma tissue in one case by polymerase chain reaction applying type-specific primers. We did not find any signs of maternofoetal transmission in the anamnesis and the maternal cervix proved to be negative for viral DNA. However, the vertical route of transmission can not be excluded due to the special natural history of papillomavirus infections. Papillomas usually localised in normal squamociliary junctions of the larynx. The histopathologic review did not reveal any signs of malignancy. Koilocytosis referring to productive viral infection and the signs of abnormal keratinisation were present in each tissue. All tissues of the patients proved to be positive for the short amplimer deriving from the genome of human papillomavirus type 11.