Introduction
The prognosis for patients with pancreatic cancer could be improved if clinicians were able to detect and treat the disease in its early stages (1,2). Using a recent analysis of the Japan Pancreatic Cancer Registry, the Japan Pancreas Society reports that the 5-year survival rate in patients with lesions less than 10 mm in diameter is 80.4%, and that it is 85.8% in patients with stage 0 pancreatic cancer, comprising high-grade pancreatic intraepithelial neoplasia (PanIN-3) and pancreatic carcinoma in situ (PCIS) (3). However, only 0.6% of patients with pancreatic cancer are diagnosed at stage 0 because of the difficulty of detecting cancer at this early stage (4). We describe herein a patient with PCIS synchronous with early gastric cancer, detected preoperatively using serial pancreatic juice aspiration cytological examination (SPACE).