STUDIES OF THE METASTATIC LYMPH NODE AND ITS IMAGES ON COMPUTED TOMOGRAPHY (CT) IN GASTRIC CANCER

The present study was designed to analyze the features of metastatic lymph nodes of gastric cancer on computed tomography (CT). Sixty-eight patients with gastric cancer who underwent D2 lymph node dissection and were found to have lymph node metastasis were subjected to the study comparing the histopathological findings with CT images of these metastatic lymph nodes. Metastatic lymph nodes were classified into four types according to the histological features: macro-nodular, micro-nodular, diffuse and micro-focal. This classification was applied to the 56 lesions in 35 patients whose lymph nodes were clearly visualized on CT and their histological features were compared with their CT images. Of the metastatic lymph nodes, the diffuse type was the most common (51.9%). The images of metastatic lymph node on CT were classified into two types: non-enhanced type (NE) (76.0%) and mottled enhanced type (ME) (24.0%). Of NE, the macro-nodular type represented 83.3%. Of ME, the macro-nodular type represented 50.0%, diffuse type 39.5%, micro-nodular type 10.5%. Lymph nodes visualized by CT were predominantly of macro-nodular type. The majority of lymph nodes presenting NE on enhanced CT were belonged to the macro-nodular type. The diffuse type lymph nodes were visualized in a low frequency, but the increase in diagnosing rate can be expected, if ME is employed as an index.