[A case of flat elevated type carcinoma in adenoma of the duodenum with gastric cancer].

Duodenal adenoma is rare, and there have been very few case reports of flat elevated type adenoma. We report a case of flat elevated type carcinoma in adenoma of the duodenum with gastric cancer. A 58-year-old man was referred to our hospital for gastric cancer. Endoscopic examination revealed the gastric cancer and a flat elevated tumor in the descending part of the duodenum, measuring 6 cm in diameter. The biopsy specimen of the duodenal lesion was diagnosed as adenoma. Distal gastrectomy and segmental partial resection of the duodenum were performed with no complication. Histologically, the gastric cancer was poorly differentiated adenocarcinoma with submcosal invasion and without lymph node metastasis, and the duodenal tumor was a well differentiated carcinoma in villous adenoma. The duodenal adenocarcinoma was limited to the mucosal layer and the resected margins were free of tumor. It is difficult to distinguish a carcinoma from a benign elevated lesion in the duodenum. Therefore, a resection of the whole tumor is necessary. Though endoscopic resection is the first choice of therapy, a surgical partial resection is necessary when it is difficult. Then, a segmental resection may be one of the useful procedures of surgery.