消化管結核の病理診断

Pathological Diagnosis of Gastrointestinal of GI Tract

要旨●消化管結核は難治性潰瘍性病変の鑑別診断として必ず挙げられる疾患で，迅速な対応，治療を行うためには各臓器でのその特徴を把握しておくことが重要である．確定診断には乾酪性肉芽腫や結核菌の検出が必須だが，生検のみで両者を確認するのは比較的困難である．活動性病変ではCrohn病との鑑別が特に重要で，潰瘍の走行や形態，肉芽腫の大きさや形態に加え，血液検査やツベルクリン反応，そして肛門部病変の有無などの臨床的所見と総合し，両者の鑑別がなされるべきである．典型的な乾酪性肉芽腫や結核菌が検出されなくても，大型で癒合性のある非乾酪性肉芽腫はCrohn病との鑑別に有用である．腸結核では輪状潰瘍の他に，病理組織学的におそらく粘膜筋板の上下を主座とした多数の潰瘍や瘢痕，それらの周囲の粘膜下層を中心とした炎症が治癒して生じたと推測される線維化が観察される．これにより生じたKerckring皺襞の不規則な走行や途絶，消失が萎縮瘢痕帯の一部として認識されると推察される．

　Gastrointestinal tuberculosis should be included in the differential diagnosis of intractable ulcerative lesions, and understanding the characteristics of each organ for immediate intervention and treatment is important.

　Detecting caseating granuloma and Mycobacterium tuberculosis is crucial for a definitive diagnosis ; however, detecting them using a biopsy specimen alone is relatively difficult.

　Distinguishing gastrointestinal tuberculosis from Crohn's disease in patients with active lesions is particularly important. Therefore, a differential diagnosis must be performed based on a comprehensive judgment of clinical findings, such as the morphology of ulcer and granuloma, in addition to blood tests, the tuberculin reaction, and the presence or absence of anal lesions.

　A large and confluent non-caseating granuloma is useful for differentiating gastrointestinal tuberculosis from Crohn's disease even if typical caseating granuloma and M. tuberculosis are not detected.

　Histologically, many ulcers and scars, primarily around the muscularis mucosae, and fibrosis, which might be generated from healed inflammation around the submucosa, are observed in intestinal tuberculosis as well as circular ulcers.

　Irregularity, blocking, and disappearance of Kerckring's folds caused by scars and fibrosis are recognized as a part of the scarred area with discoloration.