Related Experiment Video
Updated: May 2, 2026
Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery
Published on: July 5, 2021
Midgut neuroendocrine tumors: imaging assessment for surgical resection
Lorna R Woodbridge1, Bernadine M Murtagh, Dominic F Q C Yu
1From the Department of Radiology, Royal Free Hospital, Pond Street, London NW3 2QG, England.
Abstract:
Midgut neuroendocrine tumors (MNETs) are rare, and the primary tumor is usually small and difficult to visualize at imaging. Patients often present late with extensive liver and nodal metastases and may experience symptoms secondary to the release of active substances by the primary tumor, such as serotonin and its metabolites, which have local and systemic effects. Locally, this causes desmoplasia and vascular encasement and may lead to small bowel obstruction and ischemia, with significant morbidity and mortality. Systemically, the release of active substances into the circulation can cause flushing, diarrhea, and abdominal pain (carcinoid syndrome); these substances can be detected in urine and blood serum and used as markers for diagnosis and treatment follow-up. MNETs retain expression of specific peptide receptors such as somatostatin receptors, which will bind to synthetic somatostatin analogs such as octreotide. This feature is useful for functional imaging of patients with MNETs and for peptide receptor radionuclide therapy using somatostatin analogs. Resection of the primary tumor is advocated, even in patients with extensive metastases, because it may prevent development of local complications, can help control systemic symptoms, and has been shown to confer some survival advantage. Computed tomography and functional imaging are used to identify the primary tumor and assess its resectability. The main factors governing resectability are patient comorbidities (eg, carcinoid heart disease), vascular involvement, and desmoplasia.
Insights
Midgut neuroendocrine tumors (MNETs) are rare and often present with widespread metastases. Surgical resection of the primary MNET is recommended to manage symptoms and improve survival.
Area of Science:
- Gastroenterology
- Oncology
- Radiology
Background:
- Midgut neuroendocrine tumors (MNETs) are rare, often diagnosed late with extensive metastases.
- Tumor-secreted substances cause local complications (obstruction, ischemia) and systemic carcinoid syndrome.
- MNETs express somatostatin receptors, enabling targeted imaging and therapy.
Purpose of the Study:
- To review the diagnosis, management, and prognostic factors of midgut neuroendocrine tumors.
- To emphasize the role of primary tumor resection in managing MNETs.
Main Methods:
- Review of imaging modalities including computed tomography and functional imaging.
- Assessment of factors influencing surgical resectability.
- Discussion of treatment strategies including surgery and somatostatin analogs.
Main Results:
- Primary MNETs are often small and difficult to visualize.
- Late presentation with metastases is common, leading to significant morbidity and mortality.
- Surgical resection can prevent local complications, control symptoms, and improve survival.
Conclusions:
- Resection of the primary MNET is advocated, even with metastases, to improve outcomes.
- Surgical resectability depends on patient comorbidities, vascular involvement, and desmoplasia.
- Functional imaging and somatostatin receptor targeting are crucial for MNET management.
