The fifth edition of the TNM classification of malignant rumours contains s
ome additions and modifications for classifying rumours of the digestive sy
stem. Apart from the armours of the stomach the most important revisions ha
ve been made in tumours of the pancreas. In tumours of other sites of the d
igestive system only minor changes or modifications have been introduced A
new element of the pN classification cation is that the number of lymph nod
es ordinarily included in a lymphadenectomy specimen is noted at each site.
The designation pN0 is usually based on this figure.