Natural History of Duodenal Adenoma: An 11‐year Follow‐up

Early detection and treatment are essential to decrease the mortality rate of duodenal cancer (DC). However, the natural history of DC remains unclear. A 78‐year‐old woman underwent screening esophagogastroduodenoscopy (EGD) before surgery for advanced colon cancer. A 25 mm‐sized flat‐elevated lesion was detected in the second portion of the duodenum anal to the Vater's papilla. The biopsy specimen showed a tubular adenoma. The patient recovered well from right hemicolectomy and wished for periodic EGD follow‐up for the duodenal adenoma. The duodenal adenoma slowly increased in size, but a biopsy showed a tubular adenoma for 9 years. Ten years after the initial examination, biopsy showed well‐differentiated tubular adenocarcinoma, and submucosal invasion was suspected, although she did not wish to undergo surgery. The lesion finally progressed to advanced cancer 11 years later, and pancreatoduodenectomy was performed. The final stage was pT3N1M0, Stage IIIB. In this case, a duodenal adenoma progressed to advanced DC with lymph node metastasis. Early decision‐making regarding endoscopic resection is required even in older patients.