追跡例からみた食道異形成（dysplasia）―第33回食道色素研究会「食道dysplasia（異形成）を考える」のまとめを中心に

Follow-up Study of Esophageal Dysplasia: It's Diagnosis and Histological Change

要旨　食道異形成（dysplasia）の実体を知るために，経過追跡した食道異形成の症例を用いて検討した．生検診断では，提示施設の組織診断と消化器専門病理医あるいは専門病理医間での診断の乖離が大であった．また癌抑制遺伝子産物p53あるいは増殖能の指標となるKi-67の染色は癌診断に有用であり，境界領域病変の診断には参考になると思われた．今回の検討では，25例の経過追跡例中1例のみが種々の面から経過中に異形成から癌に変化した可能性があるとされ，本来の意味での前癌病変としての食道異形成と言える可能性のある病変はごく限られた症例であると思われた．一方，p53，Ki-67の免疫染色の結果からは，組織学的に非腫瘍性と思われる病変でも軽度ながら異常がみられ，遺伝子の面では組織学的に癌と診断できない病変でも遺伝子の異常が起こっている可能性があり，その意味での異形成の存在の可能性が示唆された．

　To know the true nature of esophageal dysplasia, we examined 44 follow-up cases of esophageal dysplasia.

　In biopsy of borderline lesions, there was disagreement among specialists about histological diagnosis. For example, the histological diagnosis recieved from the institution where the case was presented might differ from that of the specialist in digestive pathology.

　Immunohistochemical staining of tumor suppresser gene p53 product and Ki-67 were helpful indicators for making diagnosis more accurately. They were useful for histological diagnosis of cancer, and in particular, were useful in diagnosis of borderline lesions.

　In the follow-up period during this examination, only one of 25 lesions was regarded as a borderline lesion was changing into cancer.

　On the other hand, many lesions diagnosed as histologically non-tumor were showed weak p53 positivity by immunohistochemistry. Accordingly, from a genetic point of view, the possibility of the existence of premalignant lesion (dysplasia) was suggested.