[A comparative study of weight of regional lymph nodes in association with the presence of metastasis in primary lung cancer patients].

The weight of regional lymph nodes was measured in 173 patients who underwent surgical resection of the primary lung cancer and lymph nodes from January, 1986 to January, 1989 in our hospital. Histological examination was also performed and correlation of metastasis and the weight of lymph nodes were studied. The average weight of metastatic lymph nodes was 2.34 g while that of non-metastatic ones was 0.83 g indicating a significant (p less than 0.05) increase of weight in metastatic lymph nodes. Although the percentage of metastasis increased as the weight of lymph nodes increased, 7.6% of lymph nodes weighing less than 0.5 g was positive for metastasis. On the other hand, 66.7% of the lymph nodes weighing more than 3.0 g in adenocarcinoma and 34.5% in squamous cell carcinoma were positive for metastasis indicating the difference of the metastatic tendency to the lymph nodes between the two histological types. The comparative study of the weight of each lymph node station according to the JJC criteria demonstrated the difference of average weight of non-metastatic lymph nodes among each lymph node station. The average weight of pretracheal (#3), subcarinal (#7), interlobar (#11), and segmental (#12) lymph nodes without tumor metastasis were more than 1.0 g, however those of anterior mediastinal (#3a), paraesophageal (#8), and pulmonary ligament (#9) were less than 0.5 g. The average weight of metastatic lymph nodes in each lymph node station was in proportion to those of non-metastatic ones.