胃カルチノイド17例の臨床像―背景粘膜からみた臨床分類およびA型胃炎との関係

Clinical Features of Gastric Carcinoids Analysis of 17 Cases

要旨　過去21年間に診断された胃カルチノイド17例を背景粘膜と血清ガストリン値に基づいたRindiらの方法に従って再分類し，その臨床像を検討した．Ⅰ型13例，Ⅱ型1例，Ⅲ型3例に分類され，高ガストリン血症と萎縮性胃炎を伴うⅠ型が最も多く，Ⅲ型と比較して体部に多発する傾向が認められたが，カルチノイド腫瘍のX線・内視鏡所見や深達度にⅠ型とⅢ型で明らかな違いは指摘できなかった．次に，Ⅰ型カルチノイドを合併したA型胃炎5例とカルチノイド非合併A型胃炎14例における病理学的萎縮の程度と胃体部におけるX線・内視鏡所見を対比した．萎縮の程度は胃体部大彎皺襞，血管透見度，粘膜パターンの程度と有意に相関し，これら3つの因子を合計すると強い相関がみられた．カルチノイド合併群は若年時に診断され，血清ガストリン値が高い傾向を示したが，背景粘膜のX線・内視鏡所見や萎縮の程度に差はなかった．以上より，胃カルチノイドの診断には腫瘍のX線・内視鏡所見と背景粘膜の詳細な観察とともに，臨床像の把握が必要と考えられた．

　We classified 17 cases of gastric carcinoids according to the serum gastrin level and the histology of the background mucosa. Thirteen carcinoids were regarded to be Type Ⅰ (hypergastrinemia with atrophy of the background mucosa) while another was classified into Type Ⅱ (hypergastrinemia without atrophy) and the remaining three into Type Ⅲ (normogastrinemia) . While Type Ⅰ carcinoids occurred predominantly at the gastric corpus in multiplicity, there were no differences in the histologic and endoscopic findings of the tumor among the three types of carcinoid. We then compared clinical and histologic findings in five cases of autoimmune gastritis with carcinoid and 14 cases without carcinoid. Overall, there was a significant correlation between histologic grade of atrophy and scores for atrophy determined by radiography and endoscopy. While the grade of atrophy in the background mucosa in both groups was the same, there was a tendency that the former cases to be younger and their serum gastrin levels to be higher than the latter cases. These findings suggest that confirmation of clinical parameters, as well as background mucosa, is mandatory for the diagnosis of carcinoid in autoimmune gastritis, and possibly, for the diagnosis of Type Ⅰ gastric carcinoids.