胃・十二指腸におけるcollagenous colitis類似病変の特徴

Collagenous Gastritis, a Counterpart of Collagenous Colitis: Review of Japanese Case Reports

要旨　CG（collagenous gastritis）は，CC（collagenous colitis）と同様，粘膜固有層の細胞浸潤と上皮下に10μm以上に肥厚したcollagen bandの存在により組織学的に定義される．CGはまれな疾患であり，これまで本邦報告は5例にすぎない．自験1例を追加し検討した結果，20～43歳の比較的若年者にみられ，発見動機は検診または心窩部痛であった．X線・内視鏡像は，顆粒結節状変化が特徴的であるが，隆起周囲に認められる非びらん性の陥凹性変化が本体である．組織学的に炎症所見の不均一性を認め，腺管萎縮がまだらに起こるため，顆粒結節状に取り残しを形成すると推定された．欧米では，CCを合併し大腸や十二指腸にcollagen bandの肥厚を認めた症例が報告されているが，本邦の症例はいずれもCG単独例であった．

　Collagenous gastritis and collagenous colitis are both defined histologically as the presence of a subepithelial collagen band thicker than 10μm in association with increased inflammatory cell infiltrate of the lamina propria mucosa. Collagenous gastritis is a rare disorder, with 5 Japanese cases reported to date. A total of 6 Japanese cases were reviewed with our one additional case. Those patients were 20-43 years old, and presented for health checkup or for epigastric pain. Upper gastrointestinal barium radiography and endoscopy demonstrated mucosal nodularity surrounded by depressed mucosa, possibly resulting from heterogeneous inflammation and irregular atrophy of the mucosal gland. In Western countries some cases have been reported associated with collagenous colitis and/or collagenous duodenitis, but, in our country, they have been reported as being without colonic involvement.