Corneocyte architecture in the human external auditory canal.

Using skin dissected from the external auditory canals of fresh cadaveric temporal bones, the structure of the stratum corneum was investigated by the techniques of alkaline expansion of cryostat sections, silver staining of epidermal sheets, and scanning electron microscopy. Ordered epidermal column formation was observed in the stratum corneum from skin obtained from both the bony and cartilaginous portions of the canal. Occasionally, in areas of skin where the stratum corneum was considerably thickened, this vertical organization was lost, and the corneocytes randomly arranged. This orderly cellular architectural arrangement is a feature of the non-migratory skin of lower mammals, and has also been reported to occur in some areas of human skin. The functional relevance of this finding in the skin of the external canal is that the whole of the stratum corneum must migrate as one in order to preserve a regular vertical structure, suggesting that epidermal migration occurs in the deeper layers of the meatal epidermis.