Two programmes for examination of regional lymph nodes in colorectal carcinoma with regard to the new pN classification.

The new pN classification for colorectal carcinoma requires not only a statement on absence or presence of regional lymph node metastases but also, if present, a knowledge of the site and number of involved nodes. Subdivision of the fatty tissue with nodes adhering to the tumor resection specimen into two compartments is therefore the first step in pathological examination of lymph nodes. The methods for this as well as the different techniques used in searching for nodes and further histological processing of nodes are presented. We outline a minimal programme for pN classification in which step-wise sequence of examination reduces work load. An extended programme designed to answer special questions regarding lymphatic spread and surgical method is recommended only within the framework of special clinico-pathological studies.