同時性多発早期胃癌の2例

抄録

Recently, synchronous multiple early gastric cancers are being increasingly reported due to the aging of society and development of high-performance endoscopy techniques. We present two cases of synchronous multiple early gastric cancers in which the diagnosis was made before the treatment. In Case 1, three pedunculated lesions measuring approximately 10 mm in diameter and one depressed lesion measuring 20 mm in diameter were detected endoscopically in the gastric antrum, and examination of biopsy specimens revealed the diagnosis of cancer for all the lesions. Laparoscopic subtotal gastrectomy was performed, and histology of the resected tissue revealed intramucosal well-differentiated tubular adenocarcinoma in the three pedunculated lesions and intramucosal poorly differentiated adenocarcinoma in the depressed lesion. In Case 2, two depressed lesions measuring approximately 10 mm in diameter and one pedunculated lesion measuring 3 mm in diameter detected in the gastric body were treated by endoscopic submucosal resection. All the resected lesions were diagnosed histopathologically as intramucosal well-differentiated tubular adenocarcinomas. Histopathological examination revealed evidence of atrophic gastritis with intestinal metaplasia due to H. pylori infection in the background gastric mucosa in both the cases, and the mucin expression phenotype of the gastric cancer was the gastric phenotype in the three pedunculated lesions of Case 1 and the intestinal phenotype in all the three lesions in Case 2. We suggest that the possible presence of synchronous multiple cancerous lesions, e.g., well-differentiated adenocarcinoma located in the atropic gastric mucosa, should be investigated endoscopically in patients diagnosed as having early gastric cancer.