1990 年 21 巻 1 号 p. 9-10
Thirty guinea pigs were used in this experiment. A piece of skin taken from superior and inferior part of the external auditory meatus and from the auricle were implated subcutaneously in the back. They were removed between the 1st and the 18th week postimplantation for the histological study. Epidermal cyst was formed in all the animals beyond two weeks. Regardless of origin of the skin, the histological findings appeared to be same. No further growth of cyst was recognized after the 2nd week. In some animals, the cysts were cut in half in order to expose the contents directly to the surrounding tissue between the 2nd and the 3rd week. Even after this procedure, the size as well as the histological findings were same regardless of origin of the skin. The results suggest that the skin of superior part of the external auditory meatus has no specific growth potentiality to form epidermal cyst.