治療成績からみた食道m3・sm癌の治療方針―外科手術例におけるリンパ節転移：病理の立場から

Lymph Node Metastasis of m3 and sm Esophageal Squamous Cell Carcinoma: Analysis of 95 Surgically Resected Cases

要旨　深達度ごとのリンパ節転移の頻度およびリンパ節転移に関連する原発巣での病理組織像の特徴を明らかにする目的で，当院におけるm₃・sm癌手術例95例を病理学的に検討した．リンパ節転移は，m₃症例16例中1例（6.3％），sm₁症例10例中2例（20.0％），sm₂症例34例中12例（35.3％），sm₃症例35例中23例（65.7％）にみられ，脈管侵襲率はそれぞれ43.8％，70.0％，91.2％，94.3％であった．原発巣においてリンパ節転移を示唆する所見は脈管（リンパ管・静脈）侵襲像と小型胞巣の浸潤性増殖像と考えられた．EMRによる治療の際には，EMR検体の深達度と脈管侵襲の病理学的評価が重要である．

　Ninety-five surgically resected cases of m₃ and sm esophageal carcinoma were examined histopathologically, to evaluate the frequency of the permeation of vessels and lymph node metastasis. Lymph node metastasis was found in one of the 16 patients (6.3％) with m₃ carcinoma, two of the 10 patients (20.0％) with sm₁ carcinomas, 12 of the 34 patients (35.6％) with sm₂ carcinomas and 23 of the 35 patients (65.7％) with sm₃ carcinomas. Permeation of vessels was found in 43.8％, 70.0％, 91.2％ and 94.3％ of the m₃, sm₁, sm₂ and sm₃ lesions, respectively. In m₃ and sm₁ cases, all of the cases with lymph node metastasis showed lymphatic permeation. Moreover, most of the cases with lymphatic permeation were accompanied with infiltrative proliferation of small nests of cancer cells. In 34 sm₂ cases, 3 cases without permeation of vessels were found. In application of EMR as therapy for m₃/sm esophageal carcinomas, precise histopathological examination of resected specimens is required to clarify depth of invasion, permeation of vessels and pattern of invasion. Immunostaining with D2-40, a lymphatic endothelial marker, is a useful tool for detection of lymphatic permeation on histological slides.