表在食道癌におけるルゴール染色の診断学的価値

Value of Lugol Staining Method in Diagnosing Superficial Esophageal Cancer

要旨　ルゴール染色は通常内視鏡検査でも指摘困難な表在平坦型食道癌の描出に優れている．教室の31例の表在癌のうち1例32％はルゴール染色で発見された．また特に表在隆起型では予後に関連する分類である，露出型，粘膜下伸展型の2型の容易な識別に有用である．ルゴール染色の染色程度を5段階に分類している．Ⅰ，Ⅱは染色され，肥厚上皮，正常上皮であり，Ⅲ，Ⅳ，Ⅴは非染領域である．Ⅴは癌である頻度が高く，Ⅳは癌と異型上皮の頻度が高く，Ⅲは萎縮上皮，正常上皮であることが多い．これらの染色性，組織像の差は上皮内グリコーゲン量と上皮全層に対するグリコーゲン含有細胞の層の比に関連している．

　Lugol staining method lately come to play an important role in detecting superficial esophageal cancer that is extremely difficult by using only conventional esophagoscopy. This method is most valuable in assessing the intraepithelial spread of superficial esophageal cancer by differentiating two types of superficial elevated esophageal cancer, i.e., the exposed type and the concealed (subepithelial growing) type. We classified the findings obtained by this method into five grades; Ⅰ and Ⅱ stained normally, Ⅲ, Ⅳ and Ⅴ did not stain. We attempted to correlate the histological findings with glycogen content in the cells of the non-staining lesions. The results were that the incidence of cancer was high in grade Ⅴ, the incidences of both cancer and dysplasia were high in grade Ⅳ, and the majority of specimens in grade Ⅲ showed atrophy in otherwise normal epithelium. The proportion of non-staining lesions was related to the amounts of glycogen stored in the cells and the ratio of the layers containing glycogen to the total layers of epithelial cells.