大腸悪性リンパ腫の臨床的特徴と画像診断―組織型との対比を含めて

Clinical Features and Diagnostic Imaging of Colorectal Lymphoma―Correlation with Pathologic Findings

要旨　大腸原発悪性リンパ腫の41症例45病変についてX線・内視鏡所見の特徴と病理組織学的所見との対比について検討した．大腸悪性リンパ腫の肉眼型は隆起型・潰瘍型・びまん型の3つに分類した．肉眼型と深達度の関連では，隆起型より潰瘍型でより深い傾向にあった．病理組織学的にはびまん性大細胞型リンパ腫は潰瘍型が多く深達度が深い傾向にあり，MALTリンパ腫では隆起型が多く深達度も浅いものが多い傾向にあった．悪性リンパ腫の画像診断においては隆起部分の粘膜下腫瘍様の所見を注意深く捉えることが重要であると思われた．また腫瘍の大きさ・管腔の狭窄に比べ通過障害の症状に乏しいことも特徴的であった．

　We investigated the endoscopic and radiological findings of colorectal lymphomas from 41 cases with 45 lesions, and assessed the correlation with pathological findings. We classified morphological findings of colorectal lymphoma into three types : protruded, ulcerative, and infiltrative type. The ulcerative type lymphomas more frequently invaded to the serosa than the protruded type. Diffuse large B-cell lymphomas (DLBCL) were often of the ulcerative type, but marginal zone B-cell lymphomas from mucosa-associated lymphoid tissue (MALT) were of the protruded type and had no tendency towards invasion, compared with DLBCL. The characteristic features of colorectal lymphoma were smooth mucosal surface mimicking submucosal tumor and severe luminal narrowing without any symptom of obstruction.