Title:A Rare Case of Primary Sclerosing Cholangitis associated with Extrahepatic Biliary Neuroendocrine TumorAuthor:Nargiz Gasimova, MD, Department of Internal Medicine, Overlook Medical Centre, Summit, 07901, NJ, [email protected] author:Sharon John, Medical Student, Education-Medical department, Overlook Medical Centre, Summit, 07901, NJ, [email protected] contribution:Conceptualization, data curation, formal analysis, funding acquisition, investigation, methodology, resources, software, validation, visualization, writing original draft, writing-review & editingAcknowledgement:The authors express their gratitude to the Department of Internal Medicine and Gastroenterology at Overlook Medical CenterEthical statement:Because this was a retrospective report, we have obtained the written consent from the patient and her family before publication of relevant data. Additionally, because this was a retrospective report, our group presumed that no registration was necessary. It was clearly stated that only clinical information will be shared in research, without mentioning any personal details at any part of the article. Informed consent from the patient was considered sufficient.Funding:This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.Disclosure Statement:The authors declare that there are no conflicts of interest regarding this paper’s publication.Data availability statement:The data supporting this study’s findings are available in the supplementary material of this article.Key Clinical Message:This case report demonstrates the importance of thorough investigation and vigilance in managing primary sclerosing cholangitis (PSC), particularly due to its association with various hepatic and extrahepatic malignancies. The discovery of a neuroendocrine tumor (NET) within the extrahepatic bile ducts in a patient with PSC highlights the need for heightened awareness and comprehensive evaluation. This case underscores the complexity of the diagnostic and therapeutic approach when managing PSC, especially when complicated by the presence of additional neoplastic lesions such as NETs.