十二指腸上皮性腫瘍の内視鏡的鑑別診断

Endoscopic Diagnosis of Neoplasm-like Lesions that Should be Differenciated from Non ampullary Duodenal Adenomas and Early Cancers

要旨●最近，十二指腸腺腫や早期癌に対する内視鏡診断・治療をめぐって関心が高まりつつあるが，疾患の頻度の低さもあり，鑑別診断についてはあいまいな点が多い．腫瘍様病変としては異所性胃粘膜とBrunner腺過形成の頻度が高い．異所性胃粘膜は多発病変だと比較的診断は容易であるが，単発病変では他の腫瘍性病変（腺腫，早期癌）との鑑別診断が困難なことがある．生検による腺腫，癌の診断も容易ではなく，内視鏡診断・病理学的診断共に他の消化管に比べて課題が多いのが現状である．腸型の腺腫・粘膜内癌では絨毛の白色化が特徴的で，腫瘍性・非腫瘍性病変の鑑別診断に極めて有用な所見である．さらに腺腫と癌との鑑別診断には白色化の発現パターンや粘液形質との関連など臨床病理学的な検証が今後の課題である．

　Recently, there has been a growing interest in the endoscopic diagnosis and treatment of duodenal adenoma and duodenal early cancer ; however, these diseases occur infrequently, and their differential diagnosis is often ambiguous. During endoscopic examination, Brunner's gland hyperplasia and heterotopic gastric mucosa（HMG）, which is a neoplasm-like lesion, are most often encountered in the duodenum. Although the endoscopic diagnosis of HMG composed of multiple lesions is comparatively easy, HMG composed of a single lesion sometimes needs differential diagnosis with other neoplastic tumors, such as adenoma and early cancer. Endoscopic and pathological diagnosis and often challenges compared with other digestive tract tumor by biopsy, early cancer diagnosis is not easy, but in the present situation. Observing the characteristics of intestinal-type adenoma and intramucosal carcinoma in the whitened villi is extremely useful in differentiating neoplastic and non-neoplastic lesions. In addition to the differential diagnosis of adenocarcinoma and adenoma, future studies should focus on the clinicopathological validation expression patterns of whiting and the mucin phenotype such as.