食道“dysplasia”の存在を問う―経過観察例から食道“dysplasia”を考える

Does “Esophageal Dysplasia” Really Exist？：Reconsideration Based on Follow-up Data

要旨　食道dysplasiaの診断について，生検組織診断と内視鏡診断の経過観察例の分析から次のような結果を得た．(1) 食道m癌では，しばしば生検組織診断でatypia（mild，moderate，severe）あるいはesophagitisと診断されるが，術後の見直し診断ではほとんどsevere atypia（1回のみmoderate atypia）またはcancerと診断し直されている．(2) 生検組織診断上，atypiaと診断されるものに炎症性のものと腫瘍性のものがあり，炎症性のものはほとんど食道炎に起因し，腫瘍性のものはほとんど癌である．(3) 生検診断で1度でもatypiaとされたものは26例あるが，内視鏡所見（ルゴール染色を含む）および経過観察を合わせた最終診断では，13例が癌となり，11例が食道炎となり，1例は癌として経過観察中で，1例は4年9か月の観察で診断確定していない．以上の結果から，臨床からみた食道dysplasiaは，独立した疾患としてはほとんど存在しないことになる．

　Regarding the diagnosis of esophageal dysplasia, analysis of biopsy specimen and endoscopic findings yielded the following results.

　1. Cases of mucosal cancer had been not infrequently diagnosed by biopsy as atypia (mild, moderate, severe) or esophagitis．However, when reviewed postoperatively, all but one (moderate atypic) biopsy diagnosis were re-diagnosed as severe atypia or cancer.

　2. Biopsy diagnoses of “atypia” were divided into the two categories, i.e., inflammatory and neoplastic. While the former arose from esophagitis, the latter had already resulted in cancer by the time of final analysis.

　3. Twenty-six cases were diagnosed as having atypia by biopsy at least once in the course. The final diagnoses, taking into consideration of variable endoscopic findings (including Lugol dye spraying method) and disease course, were as follows; cancer: 13 cases, esophagitis: 11, cancer suspected: 1, undetermined at 57 th month: 1.

　Based on these results, esophageal dysplasia cannot be regarded as a clinical entity.