While performing the screening programme for colorectal cancer in Denmark, some cases of adenomas have been found. By histological analysis they were shown to be lymphomas. In this case report, two such cases are described. Screening is the subject of much debate. These cases are relevant because they showthat malignant diseases, which the program was not designed to identify, were found. When debating screening it should be taken into consideration, that secondary diseases, with the potential for earlier diagnostics and potentially better prognosis may be detected