G-type and lymphatic invasion are independent risk factors for lymph node metastasis of an sm gastric carcinoma, and proliferative activity may be a significant parameter for lymph node metastasis in cases with I-type carcinomas.

: Background : Recent advances in immunohistochemical staining have led to the proposition of a classification of gastric carcinomas based on cellular phenotypes, and the degree of biological malignancy of gastric-phenotype carcinomas has attracted particular attention. Subjects and Methods : One hundred and seven submucosal (SM) invasive carcinomas encountered in our center were examined for their histological type, cellular phenotype, and E-cadherin expression status to clarify their relationships with lymph node metastasis. Results : Eleven (10.3% %) of 107 SM gastric carcinomas were lymph node metastasis-positive. Gastric-phenotype carcinomas accounted for 20.6% %, with a lymph node metastasis rate of 27.3% % (6/22), which was significantly higher (p<0.05) than those of intestinal-phenotype carcinomas (5.9% %) and mixed-phenotype carcinomas (2.9% %). In terms of E-cadherin expression, only carcinomas with reduced E-cadherin expression showed lymph node metastasis at a rate significantly higher than that of carcinomas with normal E-cadherin expression (p<0.05). The lymph node metastasis rate (46.2% %) of gastric-phenotype carcinomas with reduced E-cadherin expression was significantly higher than those of carcinomas of other phenotypes (p<0.05). Conclusion : Since gastric-phenotype differentiated carcinomas with reduced E-cadherin expression have the potential for becoming undifferentiated, the risk of lymph node metastasis should be considered. J. Med. Invest. 54 : 159-167, February, 2007

A 64-year-old man with a chief complaint of melena visited our emergency outpatient clinic. After several examinations, he was diagnosed as a gastrointestinal stromal tumor (GIST) with liver metastasis. Surgical resection of the jejunal lesion and postoperative adjuvant therapy with STI571 for one year was performed. Due to recent immunohistological studies and introduction of STI571, the diagnosis, treatment, and prognosis of GIST are about to change profoundly. Further accumulation of cases is necessary to investigate the diagnosis, treatment, and prognosis of GIST.