Mixed ductal-endocrine carcinoma of the pancreas presenting as gastrinoma with Zollinger-Ellison syndrome: an autopsy case with a 24-year survival period

We report an autopsy case of mixed ductal-endocrine carcinoma of the pancre as presenting as gastrinoma with Zollinger-Ellison syndrome. A 38-year-old Japanese male was found to have Zollinger-Ellison syndrome and pancreatic g astrinoma, and gastrectomy and resection of the pancreatic turner were perf ormed. However, hypergastrinemia persisted, and the patient died of dissemi nated carcinomatosis at 62 years of age, 24 years after the onset of Zollin ger-Ellison syndrome. At autopsy, the main tumor was present in the residua l pancreas, and metastases were noted in many organs. In the pancreas and o ther organs, ductal and endocrine carcinoma areas were mixed and there was a gradual transition between the two. No acinar differentiation was noted. The ductal elements were positive for mucins and carcinoembryonic antigen b ut negative for neuroendocrine markers, while endocrine elements were posit ive for chromogranin A and synaptophysin and to a lesser extent for gastrin , but negative for mucins and carcinoembryonic antigen. The ductal elements comprised about 30% of the tumor cells, and endocrine elements 70%. Accord ing to the revised World Health Organization classification, our case was d iagnosed as mixed ductal-endocrine carcinoma. Our case is rare because the tumor manifested as gastrinoma with Zollinger-Ellison syndrome and the pati ent survived for 24 years. To the best of our knowledge, no such case has b een reported. Our case suggests that pancreatic endocrine tumors may evolve into mixed ductal-endocrine carcinomas.