[Gastrointestinal neuroendocrine tumors]

Area of Science:

• Oncology
• Gastroenterology
• Endocrinology

Context:

• Neuroendocrine tumors (NETs) predominantly occur in the gastroenteropancreatic system.
• Tumor location dictates histological patterns, clinical manifestations, and prognosis.
• Symptoms often arise from local mass effects or fibrosis, with carcinoid syndrome occurring in less than 10% of cases.

Purpose:

• To provide a comprehensive overview of the diagnosis, imaging, and treatment of gastroenteropancreatic neuroendocrine tumors (NETs).
• To highlight the diagnostic utility of biomarkers like chromogranin A and 5-hydroxyindoleacetic acid.
• To discuss the role of somatostatin-receptor scintigraphy, CT/MRI, and capsule endoscopy in NET evaluation.

Summary:

• Diagnosis relies on markers such as chromogranin A (serum) and 5-hydroxyindoleacetic acid (urine), with somatostatin-receptor scintigraphy as a key imaging modality.
• Complete surgical resection is the only curative treatment but is feasible in only 20% of cases.
• Somatostatin analogs are the gold standard for medical management, with investigational therapies targeting novel pathways.

Impact:

• Improved understanding of NET heterogeneity and diagnostic approaches.
• Guidance on selecting appropriate imaging and treatment modalities based on tumor characteristics.
• Foundation for developing new therapeutic strategies for gastroenteropancreatic NETs.