免疫異常における消化管腫瘍の臨床像と内視鏡診断―特にAIDS関連消化管悪性腫瘍の拡大内視鏡による早期診断について

Diagnosis of Tumor in Gastrointestinal Tract Relative to Immunological Disorder: Especially, Aim to Early Detection of AIDS Related Malignant Tumors

要旨　免疫不全状態として先天的免疫異常，臓器移植などに伴った医原性免疫異常，HIV感染，その他のウイルス感染，血液・リンパ系の腫瘍性疾患などが挙げられる。特に、HIV感染によるAIDS患者は全世界的に増加し、またAIDS関連の消化管悪性腫瘍は高頻度でみられ，その早期診断が重要な今日的課題となっている．今回，上部消化管内視鏡120例（男111例，女9例，平均40.2歳），大腸内視鏡63例（男59例，女4例，平均39.8歳）の計154例でKaposi肉腫11例，悪性リンパ腫7例，大腸癌3例を経験し，内視鏡的特徴像と鑑別診断について検討した．その結果，Kaposi肉腫は鮮やかな赤みを伴う血豆状，うろこ状を呈し，悪性リンパ腫は正常から軽度の発赤を示した．また，両者は種々の形態を示し，悪性リンパ腫でより大きな潰瘍型，隆起型を示す例がみられた．Kaposi肉腫の微小病変の拡大内視鏡観察では，病変は小さな平坦・隆起で色調は鮮やかな発赤を呈し，食道では血管網の途絶とIPCLの不明瞭化，胃では微小表面模様の腫大，小腸では腫大した絨毛，そして大腸では疎なI型pitを認め，またびらん部分で模様の消失がみられ，発赤は明瞭な境界を有した．悪性リンパ腫では同様の微細表面模様を認めたが色調は正常から淡い発赤で，発赤の境界は不明瞭であった．また，大腸癌を3例4病変認めたが腫瘍性pitから明瞭に鑑別された．一方，AIDS関連の感染症としてカンジダ真菌症，CMV，アメーバ，HSV，MACなどが経験されたが，びらん・潰瘍および隆起部分の性状を通常・拡大内視鏡観察により詳細に検討することで悪性腫瘍を含めた鑑別診断が可能であった．以上から，HIV感染者は既に悪性腫瘍のhigh risk groupという認識で，その早期診断を目的としたスクリーニングとして内視鏡診断学を位置づける必要があると思われた．

　The number of AIDS patients infected with HIV is on the increase. The rate of malignant tumors in the gastrointestinal tract accompanied with HIV infection is so high that early diagnosis is necessary. In this study, 120 upper gastrointestinal endoscopies (male : 111 patients, female : 9 patients, average age : 40.2 years old) and 63 colonoscopies (male : 59 patients, female : 4 patients, average age : 39.8 years old) were performed and 11 Kaposi's sarcomas, 7 malignant lymphomas and 3 colon cancers were detected. We examined endoscopical characteristic images and differential diagnosis in the above mentioned lesions. As a result, in case of Kaposi's sarcomas, a blood blister or imbricate pattern with bright redness was recognized. In contrast, in case of malignant lymphoma, slight redness was observed. Each endoscopic finding showed various morphologies and some of the malignant lymphomas indicated much larger protruded types or depressed types. With magnifying endoscopy, minute lesions of Kaposi's sarcomas showed reddish surface mucosa, swelling intestinal villi, sparse type I pit pattern, disappearance pit pattern in erosion and redness of the mucosa with a clear boundary. In contrast, in malignant lymphoma, though minute pit pattern was observed, surface mucosa was normal or light red and the border of redness was unclear. We detected 4 colon cancers which were diagnosed with neoplastic pit pattern. On the other hand, though we encountered candidiasis, CMV infections, amebiasis, HSV infections and MAC infections as infectious diseases related to AIDS, it was possible for us to make a differential diagnosis by full examination of erosion, ulceration or protruded areas by endoscopy (including magnifying endoscopy) in detail. We should recognize that patients infected with HIV are in one of the high risk groups for malignant tumor. Also they need to be examined by screening for early diagnosis with conventional and magnifying endoscopy.