Endoscopic ultrasonography in the diagnosis of regional lymph nodes in esophageal and gastric cancer--results of studies in vitro.

A total of 90 regional lymph nodes (43 benign/47 metastatic) from 16 surgical resection specimens of patients with esophageal and gastric carcinoma were examined in vitro by endosonography. The validity of endosonographic criteria of lymph node dignity (size, echogenicity, internal echo pattern and margin structure) was assessed using computer-supported B-mode analysis and compared to histopathological results. Of 26 lymph nodes with a diameter of more than 10 mm, 19 were metastatic (72%). The subjective assessment of the internal echo pattern (homogeneity) and the node margins by an experienced observer allowed the diagnosis of metastatic lymph nodes, but there was a high proportion of false positives (52%). Lymph node echogenicity, assessed either subjectively or by computer analysis, did not permit the differentiation between benign and metastatic lymph nodes.