Poorly differentiated endocrine carcinoma and intraductal papillary-mucinous neoplasm of the pancreas: Description of an unusual case.

Neuroendocrine tumors and intraductal papillary-mucinous neoplasms constitute histologically distinctive but relatively rare entities among pancreatic tumors. Collision of these tumors is extremely rare and causes several diagnostic problems regarding the histopathologic differential diagnosis of other pancreatic epithelial tumors. The question of whether the neoplastic populations originate from common progenitor cell or whether they represent only a fortuitous association has not been sufficiently explained.