主題 特異的な色調を示す病変の特徴と鑑別

Esophageal Lesions with Specific Color Change

要旨●さまざまな色調を示す病変が食道には存在する．verrucous carcinomaと錯角化の強い扁平上皮癌（squamous cell carcinoma ; SCC）は白色調を呈するが，前者はカリフラワー状の外観を呈することが鑑別に重要である．食道皮脂腺と食道黄色腫は黄色調を呈する．拡大観察を行うと前者では頂部に白色の小突起が，後者では上皮乳頭の配列に沿って微細な黄白色顆粒の集簇が観察され鑑別可能となる．食道メラノーシスと悪性黒色腫は黒色調を呈するが，初期の悪性黒色腫の場合には両者を内視鏡所見で鑑別するのは困難である．前者の経過観察中に隆起してきた場合には後者を疑う必要がある．化膿性肉芽腫は赤色調を呈する．表面に特徴的な白苔を伴っていれば診断は容易である．

　Many types of esophageal lesions have a characteristic change in color. Verrucous carcinoma and hyperparakeratotic squamous cell carcinoma appear whitish. These carcinomas can be differentiated on the basis of the cauliflower-like appearance of the verrucous carcinoma. Sebaceous glands and xanthomas appear yellowish. Magnified endoscopic findings of sebaceous glands are petal-shaped nodule with white protrusion at the center and smooth microvessels, while those of xanthomas are regular arrangement of small nodules with tortuous microvessels.

　Knowledge of these features leads to a correct diagnosis. Melanosis and malignant melanoma appear blackish in color. It is difficult to distinguish early malignant melanoma from melanosis. However, malignant melanoma should be suspected by the presence of a nodule in the blackish area. The lesions associated with pyogenic granuloma appear reddish in color. These lesions are easier to diagnose when their characteristic white surface coating can be observed.