Limited lymph-node recovery based on lymph-node localisation is sufficient for accurate staging.

AIMS To assess the reliability of nodal staging in colorectal carcinomas (CRCs) when only lymph nodes close to the tumour are recovered and examined histologically. METHODS Lymph nodes from CRC resection specimens were recovered into two fractions: one from around the tumour and the 3 cm sidelong bowel segment associated with it in the proximal and distal directions, and another from the remaining part of the resection specimen. RESULTS Of the 762 CRCs (239 right colon, 251 left colon, 257 rectum, 15 unspecified localisation) there were 393 node-negative and 369 node-positive cases. The median number of LNs examined was 18. The assessment of the LNs located in the close fraction (median 13) yielded an adequate qualitative nodal status in 756 patients (99.2%). In four cases (two rectal and two right colic), no LN metastases could be identified in the close-fraction lymph nodes, but nodes from the distant fraction contained metastases. Of the node-positive carcinomas which had at least one positive lymph node in the close fraction, 203 belonged to the pN1 category and 162 to the pN2 category of the Tumour Node Metastasis staging system. Only 14 cases (10 rectal, two right and two left colic tumours) were misclassified as pN1 (on the basis of lymph nodes recovered from the close fraction) although they were of the pN2 category. CONCLUSIONS In general, nodal status of CRCs may be adequately assessed by examining the lymph nodes from the close fraction around the tumour and the 3 cm sidelong bowel segment in both directions.