[Evaluation of missing diagnosis of metastatic lymph node in gastric cancer]

The missing diagnosis rate of metastatic lymph nodes in 38 cases of radical gastrectomy specimens by methylene blue staining and serial histologic section was evaluated as compared to that by routine examination of one histologic slide of palpable enlarged lympy nodes. The results showed that after 1251 lymph nodes had been picked up by palpation method, 1004 additional minute lymph nodes were dissected out following methylene blue staining with an average of 59.3 lymph nodes in each case. The methylene blue-stained lymph nodes accounted for 44.5% of the total lymph nodes, in which 32 were found to have metastasis which accounted for 13.8% of metastatic lymph nodes. The 2046 metastasis negative lymph nodes according to routine histologic examination were then serially sectioned at 45 microns distance and 25 sections were observed for each lymph node specimen. Minute metastatic foci were found in 23 lymph nodes, accounting for 9.9% of the metastatic lymph nodes. Therefore, 23.7% metastatic lymph nodes escaped detection by the routinely used histologic examination.