[Pathologic findings in colorectal cancers and discussion of their significance for tumor therapy according to stage].

The histological degree of differentiation is a valuable determinant of the malignancy of colorectal carcinomas. It correlates well with the tumour stage and has a prognostic relevance similar to the Dukes stages. Well and moderately well differentiated colorectal carcinomas showed significantly lower lymph node metastasis (35% and 45% of the cases, respectively) than the poorly differentiated tumours (70%). Among 20 carcinomas limited to mucosa and submucosa, only one poorly differentiated carcinoma produced lymph node metastases. The histological degree of differentiation of a given tumours assessed consecutively in biopsy and surgical material was identical in 81%. The degree of differentiation had to be corrected from moderate to well in only 9% of cases and in 8% from well to moderate. These corrections were without prognostic relevance. The prognostically important correction from moderate to poor histological degree of differentiation had to be made in only 2% of the cases. Therefore, the histological degree of differentiation can be accepted as an important preoperative criterium for the selection of adequate tumour therapy. An increased risk of tumour infiltration of resection margins was found only in cases with resection distances less than 1 cm from the tumour, whereas tumour infiltration of resection margins was minimal (below 1%) for distances of more than 1 cm. Consideration of the histological degree differentiation, clinical stage of tumour and sufficient distances of resection margins from tumours should lead to increased numbers of resections with preservation of sphincter function despite radical surgery.