Pathology
Adenocarcinomas of the colon vary considerÂably in histological appearance (scirrhous, papÂillary, medullary, or colloid), but the prognosis relates to the degree of invasion of the wall or spiead at the time of discovery rather than the pathological description. The distribution of tuÂmors in the colon (Fig. 41-2) is predominantly left-sided, with fully 50 per cent being within reach of a sigmoidoscope, although there seems to be an increasing tendency for tumors to be found more proximally in the colon.