Neuroendocrine neoplasms in uncommon gastrointestinal sites: A case series and literature review

Neuroendocrine neoplasms (NENs) are rare, heterogeneous tumours arising from neuroendocrine cells located throughout the body. The gastrointestinal (GI) tract is the most frequent site of origin, but lesions in unusual locations such as the duodenum, gallbladder and rectum are diagnostically challenging because of their atypical presentation and radiological appearance. This series describes three patients with NENs at uncommon GI sites, highlighting imaging findings, histopathological features and management tailored to the tumour site and grade. Contribution: Although rare, NENs at uncommon GI sites should be included in the differential diagnosis of hypervascular lesions. Accurate diagnosis requires integration of cross-sectional imaging, somatostatin-receptor PET and immunohistochemistry, guiding individualised therapy.