Pancreatic neuroendocrine tumor

Diagram showing the position of the pancreas CRUK 356

Pancreatic Neuroendocrine Tumors (PNETs), also known as islet cell tumors, are a type of neoplasm that arises from the pancreas. Unlike the more common pancreatic cancer, which usually refers to pancreatic adenocarcinoma, PNETs originate from the islet cells of the pancreas. These tumors can be either functional, producing hormones, or non-functional, not producing hormones. The symptoms, diagnosis, treatment, and prognosis of PNETs can vary significantly depending on the tumor's characteristics.

Symptoms

Symptoms of PNETs can vary widely depending on whether the tumor is functional or non-functional. Functional PNETs can cause symptoms related to hormone overproduction, such as hypoglycemia (from insulinomas), Zollinger-Ellison syndrome (from gastrinomas), or Cushing's syndrome (from glucagonomas). Non-functional PNETs may not cause specific symptoms until they grow large enough to press on other organs or metastasize, leading to non-specific symptoms like abdominal pain, weight loss, or jaundice.

Diagnosis

Diagnosis of PNETs involves a combination of medical imaging, blood tests, and sometimes biopsy. Imaging techniques such as computed tomography (CT) scans, magnetic resonance imaging (MRI), or endoscopic ultrasound (EUS) can help visualize the tumor's size and location. Blood tests may detect elevated levels of hormones produced by functional PNETs. A biopsy, where a tissue sample is taken from the tumor, can confirm the diagnosis through histological examination.

Treatment

Treatment options for PNETs depend on the tumor's size, location, whether it is functional or non-functional, and if it has metastasized. Surgical removal of the tumor is the preferred treatment when possible. For metastatic or unresectable tumors, treatment options may include targeted therapy, chemotherapy, radiotherapy, or peptide receptor radionuclide therapy (PRRT). The choice of treatment is tailored to the individual patient based on the tumor's characteristics and the patient's overall health.

Prognosis

The prognosis for patients with PNETs varies. Factors that influence prognosis include the tumor's stage at diagnosis, whether it is functional or non-functional, and the patient's overall health. In general, patients with localized tumors that can be completely removed surgically have a better prognosis. Metastatic or unresectable tumors have a poorer prognosis, but advances in treatment options have improved outcomes for some patients.

Epidemiology

PNETs are relatively rare, accounting for less than 5% of all pancreatic tumors. They can occur at any age but are most commonly diagnosed in adults. There is no clear gender predilection.

See Also

• Pancreatic cancer
• Neuroendocrine tumor
• Endocrine system
• Carcinoid