REGRESSION OF POLYPOID CARCINOMA INDUCED BY N-METHYL-N'-NITRO-N-NITROSOGUANIDINE IN THE STOMACH OF A DOG

  • 1 January 1980
    • journal article
    • research article
    • Vol. 71  (2) , 226-230
Abstract
Polypoid carcinoma in the gastric antrum of a Beagle dog induced by N-methyl-N''-nitro-N-nitrosoguanidine (MNNG) was sequentially studied by endoscopy and biopsy. An ulcer appeared on the angulus of the stomach at the 28th wk and resulted in an ulcer scar at the 42nd wk. A new depression with atypical glands arose on the ulcer scar at the 69th wk, developed an elevated border at the 77th wk and progressed to a polypoid lesion at the 90th wk. Well-differentiated adenocarcinoma in situ was found in the polypoid lesion at the 97th wk. It gradually grew with nodular change of its surface. The carcinoma was ulcerated at the 126th wk, became an elevated lesion with central depression at the 138th wk and finally regressed at the 154th wk. At necropsy on the 202nd wk, no carcinoma was found in the stomach.