実験胃癌の発育進展―イヌ実験胃癌の発生過程の追求(Ⅲ)

Follow-up Studies of Morphological Changes in N-methyl-N'-nitro-N-nitrosoguanidine Carcinogenesis in Stomach of Dogs: III. Growth of a depressed-type stomach carcinoma.

　N-メチル-N'-ニトロ-N-ニトロソグアニジン（MNNG）の投与によって，No. 3のイヌに発生した陥凹型胃癌について，その胃癌発生にいたるまでの経過ならびに初期の胃癌の発育状況を前報で述べた¹⁾．ここでは，この胃癌のその後における発育進展の状態ならびに終末像について供覧する．

　Follow-up studies by endoscopy and biopsy of a stomach carcinoma induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in a dog, No. 3, and necropsied findings of the stomach are described. IIc-like early carcinoma at the posterior wall side of the gastric angle gradually enlarged and became a deep depressed lesion with irregular marginal elevation, a so-called Borrmann 2 type in appearance at 115 weeks. Thereafter, it changed to a Borrmann 3 type-carcinoma at 181 weeks. Meanwhile, by the 170th week, a new shallow depressed lesion appeared at the anterior wall side of the angle. The lesion in the anterior wall side developed in the rate considerably rapid and was associated with the predominant lesion in the posterior wall side at 181 weeks. Biopsy revealed tubular adenocarcinoma in the former, and signet ring cell carcinoma with tubular adenocarcinoma in the latter. After steady development of stomach carcinoma over 2 years, the dog died of liver abscess at 216 weeks. Necropsy revealed a tubular adenocarcinoma infiltrating the serosal membrane at two points of the antral portion corresponding to cancerous lesions of anterior and posterior wall sides of the angle. Metastasis to a celiac lymph node was confirmed.