全身性疾患と直腸・肛門部病変―Crohn病を除く

Anorectal Changes in Systemic Disorders

要旨　全身性疾患での直腸・肛門部病変は診断と治療の両面で重要である．診断ではアミロイドーシスの確定には直腸生検が必須である．その際，アミロイドの沈着は血管壁が主体であるため粘膜下層を含めた採取が診断能を高める．アミロイドーシスの内視鏡所見は発赤・びらんなどの所見を呈するとの報告もあるが，教室例では10例中9例に異常がなかった．白血病や骨髄腫などでは免疫能の低下や制癌剤による骨髄抑制のため感染の危険や凝固系の異常による出血などがみられるが，特に肛門周囲膿瘍からの敗血症は致命的なことが多く予防が重要である．直腸の悪性リンパ腫や結核性の直腸・肛門病変では頻度の少なさから診断・治療の遅れを来す恐れがあり，注意深い観察が不可欠である．

　Anorectal changes are important not only for the diagnosis of systemic disorders but also for their treatment. Although redness and erosion has been reported as the endoscopic findings in amyloidosis, our study revealed that they were present in only one out of 10 cases, and the other 9 did not show any abnormal findings. For this reason, rectal biopsy is essential for the diagnosis of amyloidosis. In leukemia and multiple myeloma, the patients are at risk of infection and hemorrhagic diathesis due to disturbed immunity and bone marrow suppression by chemotherapeutic agents. Bleeding is a frequent endoscopic finding in these patients. As the sepsis following perianal abscess is severe, and often fatal, the abscesses must be treated effectively to prevent it. As malignant lymphoma or tuberculosis in the rectum and anus is less frequent, it often takes longer to diagnose them. Careful examination is essential for prompt diagnosis.