[The incidence and localization of colorectal adenomas and carcinomas in 4109 patients]

Findings at coloscopy were analysed retrospectively for 4109 patients (2257 women, 1852 men; mean age 62.3 [5-100] years) who had undergone a high coloscopy between 1982 and 1987. The aim was to determine the site of colorectal adenomas and carcinomas, as well as the relationship between adenoma and carcinoma. Main indications for the coloscopy were polyps at previous ambulatory endoscopy (15.4%), abdominal pain (11.3%) and changed bowel habits (11.2%). In 752 patients 1273 adenomas were detected and in 354 patients there were 374 carcinomas (333 solitary, 21 multiple). 21.6% of the adenomas and 21.4% of the carcinomas were proximal to the right flexure. In 75 of 177 patients (42.4%) with both adenoma and carcinoma both tumours occurred in the same intestinal segment. The severity of the dysplasia increased with increasing size of the adenoma. 52 adenomas (4.1%) already had evidence of malignant degeneration. But 7.7% of the adenocarcinomas were only 5-10 mm in diameter. The increasing incidence of right-sided tumour (right shift) compared with the hitherto known distribution pattern argues for total coloscopy as the primary procedure in the diagnosis of colorectal tumour.