Reassessment of Size Criteria on Lymph Node Metastasis of Gastric Carcinoma

Baik, Jun Hyun; Lee, Jae Mun; Kang, Si Won; You, Soo Youn; Shinn, Kyung Sub

Abstract

PURPOSE
To reassess the usefulness of criteria for lymph node size in predicting metastatic lymph node ofgastric adenocarcinoma and to determine appropriate size criteria.
MATERIALS AND METHODS
We reviewed the pathology of 1669 lymph nodes from 105 gastric adenocarcinoma patients and measured their long and short axis diameters. To determine the degree of lymph node shrinkage during fixation for pathologic examination, we measured the size of 105 lymph nodes both in the fresh state and on pathology slides after fixation and obtained their correlation equation ; this was used to determine the fresh-state size of the 1669 nodes. We analysed the distribution of metastatic and nonmetastatic lymph nodes according to their long and short axis and plotted a sensitivity-specificity curve to determine the appropriate size criteria for metastatic lymph nodes.
RESULTS
There were 535 metastatic lymph nodes and their mean diameter was 8.2+/-4.9mm on the long axis and 5.7+/-3.8mm on the short axis. The mean diameter of nonmetastatic lymph nodes was 4.9+/-2.8mm, 3.0+/-1.7mm on the long and short axis, respectively. There difference in size between metastatic and nonmetastatic lymph nodes was not statistically significant. The (P>0.05) distribution curve of metastatic and nonmetastatic lymph nodesoverlapped over wide range of lymph node size. We determined appropriate size criteria at the point where sensitivity and specificity curves crossed, but the form of the curves was such that this was difficult.
CONCLUSION
Appropriate size criteria on lymph node metastasis were 6.2mm for #1-6 lymph node group and 8.1mm for #7-12 lymph node group on long axis diameter and 4.0mm, 5.3mm on short axis diameter. But, even with this size criteria the expected accuracy was low(67-70%). This results showed limitation of size criteria to diagnose metastatic lymph node.