Genetic basis of a common tumor origin in the development of pancreatic mixed acinar-neuroendocrine-ductal carcinoma: A case report

Pancreatic cancer is classified as ductal, acinar, neuroendocrine carcinoma or pancreatoblastoma. Ductal and acinar cells derive from exocrine glands and neuroendocrine cells from endocrine glands; however, mixed acinar-neuroendocrine-ductal carcinoma has different histological carcinomas coexisting within a nodule. The mixed pancreatic carcinoma forms from different developmental origins and therefore requires investigation. The current case report presents a 50-year-old male who had a tumor within the body of the pancreas. Pathological examination clarified the tumor as a mixed acinar-neuroendocrine-ductal carcinoma. The ductal and acinar/neuroendocrine tumor components were isolated using laser-capture microdissection, and next-generation sequencing analysis was performed. Consequently, TP53 frameshift (p.N210fs) and KRAS missense (p.G12R) mutations were identified in both ductal and acinar/neuroendocrine tumors. These results suggested a pancreatic mixed acinar-neuroendocrine-ductal carcinoma was derived from a founder tumor clone, and supports the notion that a founder tumor clone may differentiate and transform into a diverse histological type and form a pancreatic mixed carcinoma.