腫瘍内Paneth細胞のみられた胃癌の4例

Paneth Cell in Gastric Adenocarcinoma, Report of Four Cases

要旨　腫瘍内にPaneth細胞の出現が認められた4例の胃癌症例について報告した．肉眼的には1例がBorrmann 2型進行癌で，他の3例はsm早期癌（Ⅲc＋Ⅲ型，Ⅱa型，Ⅰ＋Ⅱa型）であった．それらの占居部位はBorrmann 2型進行癌がcardiaに認められた以外は前庭部～胃角部にかけて認められた．病理組織学的には，管状腺癌を伴う膠様癌2例，異型上皮を合併する高分化型腺癌1例，高分化型腺癌のみが1例であった．Paneth細胞は比較的明瞭な管腔を有する癌腺管に出現し，かつその出現最深部は粘膜下組織に明らかに浸潤しているとみなされる癌腺管であった．更に〔症例1，2〕においては，所属リンパ節の転移巣内にもPaneth細胞の出現が認められた．腫瘍内に出現してみられたPaneth細胞の多くは，異型性の乏しい細胞であったが，その顆粒の大部分は正常小腸のPaneth細胞の穎粒に比し小さく，その染色態度は多様性を示した．〔症例1，4〕では，これらPaneth細胞に混じりPTAH染色，M-T染色で異染色性を示すimmature Paneth細胞が多数認められた．癌組織内のPaneth細胞は癌細胞の異分化の結果出現してきたと考えられた．

　Four cases of gastric carcinoma with Paneth cells are reported. One is Borrmann 2 type advanced cancer with submucosal invasion, and the others are early cancers consisting of Ⅱc＋Ⅲ type, Ⅱa type and Ⅰ＋Ⅱa type with submucosal invasion. Tumors were located in the antrum to angulus except for one advanced cancer in the cardia.

　Histologically, two revealed mucinous adenocarcinoma containing areas of well differentiated pattern in some parts and another two revealed well differentiated adenocarcinoma. Paneth cells were observed in cancer tubules which showed more differentiated pattern than other tubules, and in all cases, Paneth cells were seen under muscular mucosa. Also, in two cases (case 1, 2), Paneth cells were found both in the submucosal layer and perigastric metastasized lymph nodes. Paneth cells in carcinoma showed slight atypism, and Paneth granules found in these cells were smaller in size and weaker in staining than those found in the normal epithelium of the small intestine ; these findings mean that these Paneth cells are neoplastic. In two cases, moreover, among these Paneth cells were noted immature Paneth cells which were stained in a different manner by phosphotungstic acid hematoxylin (PTAH) and Masson-trichrome (M-T) techniques. It seems that the appearance of Paneth cells in carcinoma is based on disdifferentiation of neoplastic stem cells.