İstanbul Üniv. Tıp. Fak. Radyasyon Onkolojisi ABD In addition to the studies on the major problems of colon carcinoma, new clinical organisation and documentation researches appropriate to the current oncologic concept should be done in order to solve the practical problems. Over the last 50 years new developments have occurred on both of these problems. Many studies on reactive hyperplasias of colon have been published, and these types of cases were found to be not seldom as they were thought. Despite the new developments on the diagnosis and treatment of carcinoma of colon, still the calculations of survival rate for 5 years is very debatable .Only in the early diagnosed stages, i.e. in the stage where preventive resection is possible, the cure can be thought. In cases which show more than 5 years survival rate, the evaluation of results is a real problem. This may be explained by the study of genesis of carcinoma of colon. Correlations between carcinoma of colon and reactive hyperplasias such as coincidance, and cancer development, cause the difficulties in the evaluation of therapeutic results. Such complications are not so rare as it were thought to be. We published the benign cases selected among the patients which were thought to be malignant cases of colon and stomach .The aim of our new study is to analyse a new case and by doing so, emphasise the significance of reactive hyperplasias. Keywords :