ABSTRACT

Neuroendocrine neoplasms (NENs) are tumors originating from the diffuse endocrine system, most commonly located in the gastrointestinal (GI) tract. According to the World Health Organization classification, NENs are categorized into three main groups: well-differentiated, poorly differentiated, and mixed neuroendocrine-non-NEN. GI NENs can synthesize and secrete various biologically active substances, leading to characteristic clinical syndromes. These tumors may arise in any segment of the GI tract, and their clinical course, prognosis, and metastatic potential vary depending on the tumor location. In some cases, they may be associated with hereditary syndromes such as multiple endocrine neoplasia type 1 and neurofibromatosis type 1. Imaging modalities including ultrasonography, computed tomography (CT), magnetic resonance imaging and positron emission tomography-CT are employed for diagnosis, localization, and staging. Treatment strategies are tailored according to the tumor’s location, size, grade, and stage. This review focuses on the radiologic evaluation of GI NENs and emphasizes the role of the radiologist in their clinical management.