Morphology of the lamina propria in the human esophagus with special reference to the proprial papillae

The three-dimensional configurations of the proprial papillae in the human esophagus were observed by light microscopy, routine transmission electron microscopy, and scanning electron microscopy combined with NaOH maceration. Numerous finger-like or filiform papillae with a height of about 100m and a width at the base of approximately 30m were clearly distributed in the uppermost proprial layer at approximately equal intervals. The adepithelial surface of the proprial papillae was bordered by a reticular fiber sheet that was stained a deep black color by silver staining. The papillae possessed blood capillaries with fenestration, nerve fibers, and free cells such as lymphocytes, eosinophils, mast cells, and Langerhans-like cells. These findings clearly demonstrate characteristic three-dimensional features of proprial papillae, and their constituent cellular and structural elements in human esophagus.