炎症性腸疾患との鑑別を要した成人T細胞白血病リンパ腫の1例

Adult T-cell Leukemia/Lymphoma Involving the Extensive Areas of the Gastrointestinal Tract Resembling Inflammatory Bowel Diseases, Report of a Case

要旨　患者は67歳，男性．難治性下痢のため来院し，下部消化管内視鏡検査で全大腸に発赤斑を伴う浮腫状・顆粒状粘膜を認めた．内視鏡所見から炎症性腸疾患が疑われたが，生検組織中にT細胞マーカー陽性の異型リンパ球浸潤がみられた．小腸内視鏡を含む全消化管の精査により胃・十二指腸，空腸および回腸にも大腸病変と同様の多彩な病変が確認された．空腸生検組織中にHTLV-1 proviral DNAが陽性であったことから，成人T細胞白血病リンパ腫（ATLL）と診断した．消化管の広範囲に及ぶ炎症性疾患様のびまん性病変の鑑別疾患として，ATLLを含む悪性リンパ腫を念頭に置くことが重要と考えられた．

　A 67-year-old man was admitted because of refractory diarrhea. Colonoscopy showed diffuse edematous and granular mucosa with reddish spots in all sites of the large intestine. While a diagnosis of inflammatory diseases such as infectious colitis was endoscopically suggested, the histologic examination of biopsy specimens revealed T-cell lymphoma. By extensive procedures including double-balloon endoscopy for the whole gastrointestinal tract, similar edematous and granular mucosa with or without erythematous areas was found in the stomach, duodenum, jejunum and the ileum. Southern blot analysis revealed a monoclonal integration of HTLV-1（human T lymphotropic virus type 1）provirus DNA in the tumor cells obtained from the jejunal specimens. Based on these findings, the diagnosis of ATLL（adult T leukemia/lymphoma）was established. Our case suggests that ATLL should be one of the differential diagnoses for patients with apparently inflammatory lesions in an extensive area within the gastrointestinal tract.