A clinicopathological study of minute polypoid lesions of the colon based on magnifying fiber-colonoscopy and dissecting microscopy.

Magnifying fiber-colonoscopy reveals that adenoma, minute carcinomatous lesion in an adenoma (which is termed focal carcinoma), and mucosal carcinoma of the colon, each has its own characteristic pit pattern. Inspection by dissecting microscope of resected specimens obtained from subjects whose colonic mucosa had been considered normal, often reveals an abnormal pit pattern of less than 1 mm, and subsequent histologic examination confirms the frequent presence of incipient adenoma. Clinical magnification inspection of areas of colonic mucosa considered normal on the basis of ordinary observation, reveals pit patterns identical to those seen in resected specimens.