Comparative light, scanning, and transmission electron microscopic study of chemically induced premalignant lesions in hamster's cheek pouch.

The early chemically induced epithelial dysplastic changes in the hamster's cheek pouch were studied using light, scanning, and transmission electron microscopy. Epithelial dysplasia was noticed on the light microscopic level by the sixth week of the experiment and became marked by the eighth week. At the scanning electron microscopic level, surface alterations with features previously reported in early epithelial dysplasis in human and oral mucosa were seen by the second week of the experiment and progressed over time. These early changes were also confirmed at the ultrastructural level. The usefulness of scanning and transmission microscopy in detecting early oral epithelial dysplastic changes in this animal model is discussed.