Collision of a Pancreatic Neuroendocrine Tumor and Intra-ampullary Carcinoma: A Case Report and Review of the Literature.

This manuscript reports the case of a 75-year-old patient presenting with a collision tumor consisting of a pancreatic neuroendocrine tumor and intra-ampullary adenocarcinoma, which manifested with obstructive jaundice and was treated with primary surgical cytoreduction. Additionally, a bibliographic search of original articles was performed in the Medical Literature Analysis and Retrieval System Online (MEDLINE; via PubMed) and the Latin American and Caribbean Literature on Health Sciences (LILACS) databases to review the literature on pancreaticobiliary collision tumors. Currently, information regarding pancreatic and bile duct collision tumors is limited due to their very low incidence. There are only occasional case reports in the literature. The present case demonstrates that the definitive diagnosis is based on histopathological findings alone; furthermore, it is challenging to distinguish between a mixed neuroendocrine-nonneuroendocrine neoplasm (MiNENs) and a collision tumor with a neuroendocrine component.