Abstract
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 often 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 Å 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.