[A case of 8-cm metastatic lymph node rupture from early gastric cancer with low papillary structure].

A 79-year-old man experiencing sudden abdominal pain was admitted to our hospital. Upper gastrointestinal endoscopy and computed tomography images revealed an 8-cm lesion, suggestive of submucosal tumor in the gastric antrum and a type 0-IIc early gastric cancer in the gastric body. The tumor ruptured during preoperative examinations, which necessitated emergency D1+ distal gastrectomy. Pathological findings confirmed the penetration of the gastric cancer into the submucosa. The cancer comprised well-differentiated tubular carcinoma cells with a low papillary structure. At the submucosa, small clusters of carcinoma cells were surrounded by clear spaces. These clusters displayed a characteristic "inside out pattern" on immunohistochemical examination, suggesting that the clusters were probably incipient lesions of invasive micropapillary carcinoma. The ruptured tumor was identified as a lymph node metastasis from the gastric cancer. We herein report this extremely rare case in which lymph node metastasis from early gastric cancer enlarged and ruptured. The findings of this study suggest that the characteristic pathological type identified in this report, which signified high-grade malignancy, was associated with the rupture.