Ultrastructural features of human juvenile laryngeal papillomas

The ultrastructural organization of 12 juvenile laryngeal papillomas was investigated. Four patients were more than 40 years old but had carried the disease since childhood. The other 8 patients were 2-10 years old and had carried the disease from 1-5 years. There is regularly observed a discontinuity of the basement membrane and the basal cells of ten exhibit abundant cytoplasmic processes. In the stratum spinosum there is often found glycogen-like inclusions as well as Odland bodies and keratohyalin granules. In the superficial layers there are nuclear remnants as in parakeratosis. Virus-like particles of a diameter around 330 A have been demonstrated in a disintegrated superficial cell. The scarcity of such particles is discussed with possible regard to a transformation occurring in the superficial layers of the papilloma and to the high shedding rate of the surface cells.