病理からみた早期胃癌の深達度診断

Pathological Characteristics of the Role of Radiological Diagnosis of the Depth of Invasion in Early Gastric Cancer

要旨●内視鏡的粘膜下層剝離術（ESD）標本および手術標本の肉眼写真を用いて，早期胃癌の深達度診断に利用される肉眼所見の精度を検討した．いずれの肉眼型でも，粘膜下層浸潤を示唆する所見単独では特異度は高いが感度は低かった．しかし，所見を組み合わせて総合判断することで，特異度は高いまま感度が高くなった．特に特異度が高く粘膜下層への深部浸潤を示す所見は，隆起病変では“隆起頂部の陥凹”，癌巣内潰瘍のない陥凹主体病変では“台状挙上”であった．癌巣内潰瘍のある陥凹主体病変では“台状挙上”，“陥凹内無構造”，“ひだの癒合”で特異度が特に高かったが，所見の有無で腫瘍の粘膜下層浸潤距離には大きな差がなかった．早期胃癌の深達度診断は，用いる肉眼所見の特徴や限界を把握したうえで行う必要があると考えられた．

　We examined the accuracy of macroscopic findings for the diagnosis of the depth of invasion in early gastric cancer using photographs of resected specimens obtained from endoscopic submucosal dissection or surgery. In any macroscopic type, findings suggesting submucosal invasion alone showed high specificity but low sensitivity. However, when the findings were combined, increased sensitivity was observed and specificity remained high. Highly specific findings that indicated deep submucosal invasion were “depression on top of the protrusion,”in a protruded lesion; and“table-like elevation,” in a depressed lesion without ulceration. In a depressed lesion with ulceration, findings of“table-like elevation,”“non-structure in the depression,”and“fusion of folds”particularly showed high specificity. Regardless of the presence or absence of these findings, there was no significant difference in depth submucosal invasion of the tumor. For a diagnosis of the depth of invasion in early gastric cancer, it may be necessary to understand the features and limitations of macroscopic findings.