低異型度のBarrett食道腫瘍性病変の臨床病理学的検討

Clinicopathological Analysis of Low-grade Neoplastic Lesions of Barrett's Esophagus

要旨●Barrett食道に関連した異型上皮の定義は明確でなく，良悪性の判断や範囲診断に悩む症例が少なくない．今回，Barrett食道腺癌症例（ESD，手術検体）を低異型度病変に注目して検討したところ，ESD症例においては病変の中心部では明らかな異型を有しているものの，周囲では境界が不明瞭となる症例が多く観察された．しかし，顕著な異型を伴わない腺管のみから成る病変は多くなく，そのような病変では明らかな浸潤性増殖を行うものは認められなかった．粘膜の厚さも重要な因子であり，薄くても癌と判断できる部位もあるが，0-IIb型病変ではmassiveな浸潤性増殖を伴うことはまれと考えられる．一方，病変内での組織の多彩性がみられることから，生検診断の結果については慎重な判断が必要である．

　Many cases suffer from difficulty in diagnosis due to the unclear definition of atypical epithelium associated with Barrett's esophagus. We examined Barrett's adenocarcinoma cases（ESD［endoscopic submucosal dissection］, surgical specimens）with a focus on low-grade lesions in this study, and found that many ESD cases had clear atypia in the center but indistinct borders in the periphery. There were not many lesions consisting of only glandular ducts without significant atypia. Such lesions did not show obvious infiltrative growth. Mucosal thickness is an important factor, and although we have encountered some thin mucosal cancers, 0-IIb lesions rarely have massive invasive growth. The variety of tissues within the lesion requires careful judgment regarding the results of biopsy diagnosis.