大腸腺腫の組織発生―特にヒト家族性大腸腺腫症における微小腺腫の発生様式について

Morphogenesis of Colonic Adenomas with Special Reference to Mode of Development of Minute Adenomas in Familial Adenomatosis Coli

要旨　ヒト大腸腺腫の組織発生について，特に微小腺腫の発生様式の解明を試みた．ヒト家族性大腸腺腫症6症例の平坦な粘膜の，微小腺腫病変を完全連続切片法を用いて観察した．その結果，腺腫は正常腺管の増殖帯から，粘膜固有層に発芽する異型上皮の増殖巣，すなわち“腺腫の芽”として最初に観察された．正常腺管上皮の上方への移動に伴って，腺腫の芽も上方に移動し，かつ増殖して，粘膜表層部で正常腺管と分離・独立して，単一腺管腺腫となる．しかし完全に分離せずに正常腺管の開口部を占拠する単一腺管腺腫も少数例観察された．この腺腫発生の過程には，増殖帯の拡大や逆転というような異常は関与していないことがわかった．

　The morphogenesis of colonic adenomas was investigated in human tissues from six cases of familial adenomatosis coli by complete serial sectioning. Minute adenomas, consisting of a few atypical glands, were located in the upper part of the mucosa. Single gland adenomas, consisting of single atypical glands, were also located in the upper to superficial part of the mucosa with endophytic growth. Moreover, lesions smaller than single gland adenomas were detected in this investigation. These lesions, buds of single gland adenomas, consisting of epithelial clusters with mild atypia, were located in the middle part of the mucosa and sprouted from normal crypts to the lamina propria. It is concluded that buds of single gland adenomas originate in the proliferative zone of normal crypts, sprout out to the lamina propria mucosae, move upwards with migration of the epithelial cells of the crypts and are identified as single gland adenomas in the upper part of the mucosa.