pancreatic neuroendocrine tumor
A neoplasm arising from pancreatic islet cells that may secrete hormones or remain functionally inactive.
Full Definition
Pancreatic neuroendocrine tumors (PNETs) are rare malignancies originating from the endocrine cells of the pancreatic islets of Langerhans. These tumors are classified as functional or non-functional based on whether they produce clinical syndromes from hormone hypersecretion. Functional PNETs include insulinomas, gastrinomas, glucagonomas, and VIPomas, each associated with distinct clinical presentations. Non-functional PNETs are more common and typically present with mass effect symptoms or are discovered incidentally. Tumor grading is based on mitotic rate and Ki-67 proliferation index, which influences treatment decisions and prognosis. Management options include surgical resection, medical therapy, and targeted treatments.
Usage
Usage note: Preferred term over older 'islet cell tumor' terminology.
In Context
- "The pancreatic neuroendocrine tumor showed a Ki-67 index of 15%, indicating intermediate-grade malignancy." — Pathology report
- "Octreotide scintigraphy revealed multiple pancreatic neuroendocrine tumor metastases in the liver." — Nuclear medicine report