十二指腸にみられた迷入胃粘膜組織よりなるポリープの1例

A Case of Duodenal Polyps Arising from the Aberrant Gastric Mucosa

　十二指腸のいわゆる良性腫瘍は非常に稀な疾患である．Raiford（1932）¹⁾によれば，手術45,000例，剖検11,500例，計56,500例のうち，小腸に腫瘍を発見したものは88例（0.16％），良性のものは50例にすぎない．このうち十二指腸に認めたのは13例（全体の0.02％）である．またHoffmann（1945）²⁾も同様に68,000例中14例の十二指腸良性腫瘍を報じている．中村（1969）³⁾らの綜説によれば，最近までの報告例は欧米422例本邦87例である．十二指腸良性腫瘍の病理組織型は多彩であるが，迷入胃組織より発生したと考えられる症例は，本邦ではまだその報告はない．

　今回われわれは，かなり大きな十二指腸有茎性ポリープで，しかも病理組織学的に迷入胃粘膜組織から発生したと考えられるきわめて珍らしい一例を経験したので，ここにその症例を報告し，若干の考察を加えたい．

　Two unusually large doudenal polyps considered to have arisen from the aberrant gastric mucosa are reported first in this country.

　In a G-Ⅰ series of a 69 years old man with hypochromic anemia, probably caused by bleeding in the gastrointestinal tract, two polyps were found in the duodenum. As bleeding was strongly suspected from them, polypectomy was performed, though subsequent biopsy under direct vision did not reveal any malignant evidence.

　The larger polyp had a stalk 1.0 cm long with its spherical tip 1.5 cm in diameter. The smaller one was sessile the size of a red-bean. Some fissures were recognized on their both slightly nodulated surfaces.

　Histologic study revealed that the surface of both polyps was made up of hyperplastic epithelial cells, similar in structure to gastric foveolar epithelium, and was alcianophobic as demonstrated by aclian blue-PAS double staining. Underneath there was recognized fundic gland tissue, suffciently diflerentiated to chief and parietal cells.

　As metaplastic change of the doudenal mucosa into the gastric mucosa can hardly be conceivable, it would be more reasonable to assume that the genetic ground of these polyps must have been aberrant gastric mucosa in the duodenal bulb.