病理からみた早期食道癌の定義と肉眼診断

New Definition and Macroscopic Characteristics of Early Carcinoma of the Esophagus

要旨　リンパ節の組織検索ができた食道の扁平上皮ep癌11例，mm癌8例，sm癌37例，とそれができなかった症例を加えた，ep癌88病巣，mm癌17病巣，sm癌48病巣を用いて，現行早期食道癌の定義の正否，否なら新しい定義とその肉眼診断および肉眼型分類をどのようにしたらよいかを検討した．n(＋)はep癌，mm癌で0％，sm癌で30％であった．ly(＋)はep癌で0％（病巣数でみても0％），mm癌で13％（同様に6％），sm癌で65％（同様に60％）．v(＋)はep癌で0％（病変数で0％），mm癌で13％（同様に6％），sm癌で68％（同様に63％）であった．患者5年生存率はep・mm癌で90～100％，sm癌で49～65％，再発率はep・mm癌0％，sm癌10％と言われている．したがって，早期食道癌は“リンパ節転移に関係なく，粘膜内癌”と定義されるべきである．肉眼形態も，m癌とsm癌の両者で異なっていた．肉眼型のうち，早期胃癌肉眼型に対応するⅠ型やⅢ型癌ないし部分的に，それらの型を有する癌はsm癌に属，Ⅱa型，Ⅱb型，Ⅱc型，Ⅱa＋Ⅱb型，Ⅱc＋Ⅱb型はほとんどが早期食道癌，ep癌，mm癌に属した．

　In Japan, early carcinoma of the esophagus is defined as carcinoma invading down to the submucosa without lymph nodal metastasis, and superficial carcinoma as that limited to the mucosa or submucosa regardless of nodal metastasis. Such usage is complicated and inconvenient.

　We reevaluated the present definition and tried to make a new definition of esohageal early carcinoma and find out its macroscopic characteristics.

　Our files had 11 ep-carcinoma cases (intraepithelial squamous cell carcinoma), 8 mm-carcinoma cases (scc. invading the lamina propria mucosae or muscularis mucosae), and 37 sm-carcinoma cases (scc. invading the submucosa), which were all examined on resected lymph nodes histologically. To the number of the tumors of these cases were added the tumors of other cases without histological examination of lymph nodes. In total, there were 88 lesions of ep-carcinoma type, 17 mm-carcinoma type, and 48 lesions of sm-carcinoma type.

　Lymph nodal metastasis was negative in all of the ep-carcinoma and mm-carcinoma cases, but positive in 30% of the sm-carcinoma cases. Lymphatic permeation was 0% in all ep-carcinoma lesions, 6% in the mm-carcinoma, and 60% in the sm-carcinoma, while venous permeation was 0%, 6% and 68% respectively in each. It is reported that 5-year-survival rate is 90-100% in epcarcinoma and mm-carcinoma patients, and that recurrence-rate is 0% in ep-, mm-carcinoma and 10% in smcarcinoma.

　Therefore, early carcinoma of the esophagus should be defined as intramucosal carcinoma regardless of lymph nodal metastasis.

　Intramucosal carcinoma was distinguished by swelling of the circular folds, or granular mucosa with a white or yellowish-white or yellowish-brown color in the formalin-fixed material, and it belonged to one of the macroscopic types, i.e., Ⅱa type (1 mm or less in height), Ⅱb type, Ⅱc type (down to 0.5 mm in depression), Ⅱa+Ⅱb type or Ⅱc+Ⅱb type.

　On the other hand, submucosal carcinoma had features of a 5 mm or more mucosal nodule or aggregated nodules with smooth-surface, brown color and often surface-erosions (Ⅰ type, more than 1 mm in height), or a smooth-surfaced, brown, and eroded depression (Ⅱc-type), or still deeper depression (Ⅲ-type).