まれな食道良性腫瘍および腫瘍性病変の内視鏡診断

Endoscopic Diagnosis for Benign Tumor and Neoplastic Lesion of the Esophagus

要旨　食道の良性腫瘍は頻度が低く，自覚症状に欠けるため，内視鏡検査や食道造影検査時に偶然発見されることが多い．治療の適応例は少なく，経過観察例が大半を占めるが，なかには悪性腫瘍との鑑別が必要な症例や，治療対象となる症例もある．食道の良性腫瘍には，上皮性腫瘍と非上皮性腫瘍があり，上皮性腫瘍は，特徴的な形態から容易に診断できるが，表面を正常上皮が覆う非上皮性腫瘍は，通常観察だけでは診断困難であり，超音波内視鏡検査やMRI，CTなどを併用し診断するが，最終的には，粘膜下に存在する腫瘍組織を確実に採取し，組織学的に診断することが必要である．非上皮性腫瘍を発見した場合は，①形状，②大きさ，③色調，④硬さ，⑤表面性状，⑥陥凹や潰瘍形成の有無，⑦多発性の有無などについて観察する．大きさ3cm以上，表面不整で結節状などを呈し，陥凹や潰瘍を有するもの，また，短期間に急速に増大するものは，悪性の可能性が高い．

　As there are usually no symptoms associated with esophageal benign tumors, they are often found first by endoscopy or double-contrast radiographic examination. Whereas most of them need no treatment but only observation, some cases need differential diagnosis from malignant lesions, and few cases are indicated the treatment.

　Benign esophageal tumors are classified into epithelial tumor and non-epithelial tumor. The diagnosis of benign epithelial tumor is performed easily because of the characteristic appearance. On the other hand, the differential diagnosis of non-epithelial tumor covered by normal epithelium was hard to achieve by conventional endoscopy, and use together with EUS, MRI and CT. To determine the diagnosis, pathological examination by a biopsy specimen of the submucosal tissue is essential.

　When an esophageal benign tumor is detected, it should be defined by its shape, size, color, solidity, surface appearance, presence of depressions, ulcer, or multiple lesions, etc. The findings of a size over 3cm, irregular surface, accompanied by depressions or ulcerations, and features of rapid growth frequently represent malignant manifestations of these lesions.