Abstract
A 69-year-old man was under follow-up for multiple submucosal tumors in the duodenum diagnosed 14 years earlier. In the history of present illness, the patient was referred to our hospital because some of the tumors had changed in characteristic to excavating tumors. Upper gastrointestinal endoscopy showed large submucosal tumors measuring about 10 mm each in diameter in the anterior and posterior parts of the duodenal bulb. Only the lesion in the anterior wall was diagnosed as a NET by biopsy. Despite that, we judged it necessary to perform lymphadenectomy, as the tumors were larger than 10 mm in diameter. Therefore, we performed distal gastrectomy with lymphadenectomy. The resected specimen consisted of four submucosal tumors. Immunostaining showed numerous synaptophysin-positive plasma cells and chromogranin A -positive plasma cells in each of the tumors. On the basis of the histopathological findings, we diagnosed the patient as a case of NET G1, pT2N0M0, Stage IIA (ENET). Only one of the tumors could be diagnosed preoperatively as a NET. Our experience of this case shows the importance of careful endoscopic analysis for multicentricity in patients with duodenal NETs.
