Small Bowel Neuroendocrine Neoplasms.

Small bowel neuroendocrine neoplasms (SB-NENs) are a distinct subgroup of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), characterized by marked biological heterogeneity and a high prevalence of metastatic disease at diagnosis. Their frequently nonspecific clinical presentation, together with small and often multifocal primary lesions, poses significant diagnostic and therapeutic challenges. This review provides a comprehensive overview of SB-NENs, focusing on recent epidemiological trends, key elements of the 2022 World Health Organization (WHO) classification and of the American Joint Committee on Cancer (AJCC) Staging System, and the central role of imaging in clinical management. Emphasis is placed on the complementary value of anatomical and molecular imaging modalities for tumor detection, staging, treatment planning, and response assessment. The key radiologist's contribution to surgical planning is discussed, along with imaging strategies for follow-up and evaluation of treatment response.