リンパ腫様胃症—鑑別のポイントを中心に

Lymphomatoid Gastropathy：Focusing on Differential Diagnosis

要旨●リンパ腫様胃症（lymphomatoid gastropathy）は胃の良性NK/Tリンパ球増殖症で，臨床的に数か月で自然消退する特徴がある．内視鏡的には発赤の強い1cm弱の小隆起もしくは陥凹性の病変を認め，“血豆様”とも表現される．病理組織学的には，粘膜固有層に細胞質内に好酸性顆粒を有する中型リンパ球の密な増殖から成り，上皮の変形を伴うNK細胞性lymphoepithelial lesionを伴う．鑑別疾患としては，内視鏡的にも病理組織学的にも悪性リンパ増殖性疾患が問題となる．

　Lymphomatoid gastropathy is a benign NK/T lymphoproliferative disease of the stomach, clinically characterized by spontaneous regression within months. Endoscopically, a small protruded or depressed lesion of less than 1cm with strong redness is detected, and is referred to as “blood blister-like.” Pathologically, it comprises a dense proliferation of medium-sized lymphocytes with eosinophilic granules in the mucosa, accompanied by NK-cell lymphoepithelial lesions with epithelial deformation. The malignant lymphoproliferative disease is a differential diagnosis, both endoscopically and pathologically.