Close-Packed Array of Virus-Like Particles within Cells of a Human Skin Papilloma. ∗

Abstract

Summary

Intracellular spherical particles have been identified under the electron microscope in thin sections of a particular type of human wart which yields similar particles in ground suspension. In cells of the Malpighian layer of the neoplastic epidermis constituting the papilloma, the particles lie in the nucleus, but have not been recognized in the cytoplasm or in the intranuclear inclusion body or in the discrete cytoplasmic masses characteristic of this type of wart. In cells of the lower stratum corneum of the wart where the nucleus is not recognizable the particles occupy all of the cell except for a narrow peripheral border. The arrangement of the particles is generally regular and like that of close-packed spheres.