Summary

Neuroendocrine tumors (NETs) are a group of rare, heterogenous neoplasms that maintain unique morphologic and clinical features of neuroendocrine neoplasia and account for approximately 0.5% of all newly diagnosed malignancies. NETs are divided into two groups based on their histopathological morphology: well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Well differentiated NETs are classified as G1, G2, or G3 based on their proliferation rate, whereas NECs are highly proliferative and poorly differentiated by definition [1]. Neuroendocrine neoplasms can occur almost anywhere in the body; however, they are most often seen in the gastrointestinal tract, pancreas, and lungs [2]. The extrahepatic bile duct is one of the rarest primary sites for NETs, accounting for 0.1% to 0.2% of NETs of the gastrointestinal tract [3]. Signet ring cell bile duct NETs are extremely uncommon and have no established incidence and prognosis due to their rarity. There is sparse information available regarding these tumors, and only a few cases have been reported in the literature to date. In this report, we presented the clinical course and surgical management of a 31-year-old female patient with a Klatskin signet ring cell NET.