Ultrastructure of the oral epithelium in leukoplakia associated with tylosis and esophageal carcinoma.

Ultrastructural studies have been carried out on epithelium taken from the oral lesions of tylosis-related leukoplakia and preleukoplakia in a group of patients known to be at high risk for esophageal carcinoma. Several structural abnormalities are described; in particular, the presence of intranuclear electron dense particles 90 nm in diameter. Similar particles have been found in the nuclei of epithelial cells from an esophageal carcinoma developing in one of the patients under study.