非乳頭部十二指腸癌の臨床病理学的特徴—M癌と浸潤癌の相違を中心に

Clinicopathological Characteristics of Non-ampullary Duodenal Carcinoma：Focus on the Difference between Intramucosal and Submucosal Invasive Carcinoma

要旨●非乳頭部十二指腸癌34例の臨床病理学的特徴について検討し，癌細胞の粘液形質に基づいて腸型（n＝19），胃型（n＝13）および無形質（n＝2）に分類した．腸型腺癌の割合は，粘膜内癌（M癌）で88%（7/8）に対し，粘膜下層以深に浸潤する癌では46%（12/26）であり，進行度とともに胃型・無形質型の癌の割合が高くなると考えられた．胃型形質の早期癌は4例中3例が粘膜下層浸潤癌であり，うち2例には脈管侵襲ならびに切除後の再発，転移を認めた．少数例での検討ではあるが，既報告と同様に胃型は腸型と比して悪性度が高い傾向が認められ，特に早期癌であっても胃型の癌は転移，再発のリスクがある点に注意が必要と考えられる．

　We retrospectively analyzed the clinicopathological characteristics of 34 non-ampullary duodenal carcinomas. We classified these tumors into intestinal（n＝19）, gastric（n＝13）, or null（n＝2）type based on their mucin phenotype. The proportion of intestinal-type adenocarcinomas was 88%（7/8）for intramucosal carcinomas and 46%（12/26）for carcinomas invading the submucosa or deeper, indicating that the proportion of gastric and null type carcinomas increased with disease progression. Twelve out of 34 cases were early cancer, 8 being the intestinal phenotype and 4 being the gastric phenotype. Three of the four cases of gastric-type early cancer were submucosal invasive carcinomas, with two cases showing vascular invasion, recurrence after resection, and metastasis. Although the number of cases analyzed in this study is limited, note that gastric-type carcinomas tend to be more malignant than intestinal-type carcinomas and thus present a risk of metastasis and recurrence, even at early stages.