[A morphological study of human epipharyngeal mucosa: 10 autopsy cases]

The epipharynx lies between the nasal cavity and the mesopharynx, which is behind the oral cavity. It is a conduit for respired air, contributes to the equalization of pressure within the middle ear space via the eustachian tube and is closed by the soft palate during swallowing of food and fluid. It acts as a drainage channel for the mucous secreted by the nose and the glands within the epipharynx area. Various exchanges of the epipharyngeal mucosa occur because of the function of the epipharynx. In this study, distribution of the 3 types of epithelium in the epipharynx, which are ciliated, transitional and squamous epithelium, was investigated. The specimens of the mucosa with the bony wall of the epipharynx were collected from 10 autopsy cadavers at, (6 males and 4 females, aged from 37 to 83 years). Distribution of the 3 types of epithelium differed with the type, but there was no marked difference between the right and left halves of the epipharynx. Therefore, the distribution pattern was investigated by drawing superimposed geographical schemata of the epithelia, which were confirmed histologically in all 10 cases. The results obtained were as follows. On the superior-posterior wall, the squamous epithelium was invaginated into an area of the ciliated epithelium just like islands or bands in the nasal side and the epithelia of all 3 types were mixed in the mesopharyngeal side. The lateral wall was covered with a mixture of ciliated and transitional epithelia on the nasal side from the posterior lip of the eustachian tube and with a mixture of transitional and squamous epithelia on its mesopharyngeal side. The inferior wall was covered mostly with ciliated epithelium on the nasal side and with squamous epithelium on the mesopharyngeal side from Passavant's ridge. The transitional epithelium was distributed like an island between the areas of the ciliated and squamous epithelia in the lateral wall. The clearly definite schema of the 3 types of epithelium in the epipharynx, reported by Ali, has been generally accepted. However, the 3 types appeared as a mosaic or an island in the epipharyngeal wall and their distribution pattern was different in each individual.