Macro- and microanatomy of the lateral border of the tongue with special reference to oral hairy leukoplakia

The macro- and microanatomy of the marginal tongue mucosa were studied. Tissues were harvested from 12 individuals at autopsy. Random sections from six different locations along the margin and serial sections representing three defined section planes to the margin of the tongue were evaluated. Vertical, parallel mucosal folds alternating with shallow grooves were a characteristic macroscopical findings on the lateral border of the tongue. The mucosa presented a non-keratinized epithelium with PAS-positive, lightly stained spinous cells and no or slight inflammatory reaction in the connective tissue. Changes in the epithelium mimicking hyperplasia, acanthosis, keratin projections, and focal parakeratosis could be produced by changing the direction of tissue sectioning. The macro- and microscopical parameters recorded in normal marginal tongue mucosa are among other included in criteria for diagnosing oral hairy leukoplakia. The results emphasize the importance of a thorough knowledge of the normal anatomy of a mucosal site to arrive at reliable diagnostic criteria.