Electron Microscopic Study of Human Laryngeal Papillomatosis.

Sixteen biopsies of laryngeal papillomas from patients 4-21 years old, as well as tissue from scarred areas of laryngeal mucosa which previously bore papillomas, were studied with the electron microscope and compared with normal laryngeal mucosa. Tissue blocks that contained cytoplasmic bodies by light microscopy were serially sectioned for electron microscopic examination. The bodies appeared to consist of membrane-bound cell remnants such as mitochondria, lipides, endoplasmic reticulum, and nucleus. No viral particles were detected. Several ultrastructural aspects of laryngeal papillomas, including forms of cytoplasmic bodies not apparent by light microscopic examination, are illustrated. The need for further biologic studies of laryngeal papillomas and for careful electron microscopic investigation of the spectrum of cellular alterations in hu man neoplasms is indicated.