Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel

The Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel panel contains 7 tests with 6 biomarkers .

Overview of the Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel

The Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel is a comprehensive diagnostic panel designed to evaluate the presence and behavior of functional neuroendocrine tumors originating in the pancreas. These rare tumors, collectively referred to as PanNETs, arise from hormone-producing islet cells and can secrete excessive amounts of biologically active hormones into the bloodstream. Each tumor type is typically associated with the overproduction of a specific hormone, which can cause distinct and sometimes severe clinical syndromes. This panel measures multiple hormone levels to assist in identifying and classifying these tumors, guide clinical management, and monitor disease progression or recurrence.

When and Why the Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel May Be Ordered

This panel is typically ordered when a healthcare provider suspects the presence of a hormone-secreting pancreatic tumor based on clinical signs and symptoms. These may include unexplained hypoglycemia, persistent diarrhea, abdominal pain, ulcers, flushing, or symptoms of hormone excess such as hyperglycemia or gastric hypersecretion. The panel may also be used for surveillance in individuals with genetic syndromes like Multiple Endocrine Neoplasia type 1 (MEN1), which predispose them to PanNETs. Additionally, the panel plays a crucial role in monitoring known cases of pancreatic neuroendocrine tumors during and after treatment to evaluate therapeutic response or recurrence.

What the Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel Checks For

This panel detects elevated levels of hormones that may be secreted by functional pancreatic neuroendocrine tumors. Each marker corresponds to a particular tumor subtype or hormone-related syndrome.

Chromogranin A is a general marker of neuroendocrine activity and is elevated in most PanNETs, both functioning and non-functioning. It reflects the secretory activity of neuroendocrine cells and is useful for diagnosis, monitoring, and assessing tumor burden.

Gastrin is elevated in gastrinomas, tumors that secrete excessive gastrin and cause Zollinger-Ellison syndrome. This leads to gastric acid hypersecretion, peptic ulcers, and chronic diarrhea.

Glucagon is associated with glucagonomas, rare tumors that secrete glucagon, resulting in hyperglycemia, weight loss, skin rashes (necrolytic migratory erythema), and anemia.

Insulin is overproduced in insulinomas, which cause recurrent episodes of hypoglycemia due to unregulated insulin secretion, often with symptoms like confusion, fainting, or seizures.

Pancreatic Polypeptide (PP) is secreted by PPomas, which are typically non-functional tumors but may occasionally present with diarrhea or weight loss. Elevated PP levels may also serve as a general marker of PanNET activity.

Proinsulin is a precursor to insulin and may be elevated in insulinoma patients, even when insulin levels are borderline or normal. Measuring proinsulin helps identify insulin-secreting tumors with atypical biochemical profiles.

Vasoactive Intestinal Polypeptide (VIP) is elevated in VIPomas, tumors that cause Verner-Morrison syndrome (WDHA syndrome: watery diarrhea, hypokalemia, and achlorhydria). These tumors lead to profound electrolyte disturbances and dehydration.

Conditions and Diseases the Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel Can Detect

The panel is specifically designed to detect functioning pancreatic neuroendocrine tumors (PanNETs). These tumors are classified based on the hormone they predominantly secrete, and each results in a distinct clinical syndrome.

Insulinoma
Insulinomas are the most common functional PanNETs and secrete excess insulin, often leading to dangerously low blood sugar levels. Patients may present with confusion, blurred vision, tremors, or even loss of consciousness. Elevated insulin and proinsulin levels during hypoglycemia are diagnostic.

Gastrinoma (Zollinger-Ellison Syndrome)
Gastrinomas secrete excess gastrin, causing excessive gastric acid production, leading to peptic ulcers, gastroesophageal reflux, and diarrhea. Elevated fasting gastrin levels, especially with low gastric pH, suggest this tumor.

Glucagonoma
These tumors produce excess glucagon, a hormone that raises blood sugar. Glucagonomas are associated with diabetes-like symptoms, weight loss, and a characteristic skin rash. High glucagon levels support diagnosis.

VIPoma
VIPomas secrete vasoactive intestinal polypeptide, resulting in profuse, watery diarrhea, hypokalemia, and metabolic acidosis. This condition is often severe and can lead to life-threatening dehydration. Elevated VIP confirms the diagnosis.

PPoma
Pancreatic polypeptide-secreting tumors (PPomas) are usually non-functional but can occasionally cause nonspecific gastrointestinal symptoms. Elevated PP may also serve as a tumor marker for other neuroendocrine tumors, especially when combined with Chromogranin A.

Non-functioning PanNETs
While non-functioning tumors don’t secrete hormones that cause syndromes, they may still elevate general markers like Chromogranin A or pancreatic polypeptide. These tumors are often discovered incidentally or at a late stage due to mass effects.

How a Healthcare Professional Uses the Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel Results

Insulinoma
Elevated insulin and proinsulin levels during an episode of hypoglycemia confirm the diagnosis. Following treatment, these levels are monitored to detect recurrence. Suppression of proinsulin is particularly helpful in identifying subclinical residual disease.

Gastrinoma (Zollinger-Ellison Syndrome)
Elevated fasting gastrin levels are diagnostic, particularly when paired with gastric pH measurement. Healthcare providers use these results to guide imaging, initiate proton pump inhibitor therapy, and assess surgical resectability. Gastrin levels are tracked to evaluate recurrence post-surgery.

Glucagonoma
Diagnosis is based on elevated glucagon levels in the presence of characteristic symptoms. After treatment, glucagon is monitored to assess the success of surgical resection or response to systemic therapies such as somatostatin analogs.

VIPoma
High VIP levels confirm diagnosis in the context of secretory diarrhea and electrolyte imbalance. Post-treatment, normalization of VIP correlates with clinical improvement. Persistently elevated VIP may indicate residual or metastatic disease.

PPoma
Although typically asymptomatic, elevated pancreatic polypeptide levels may help identify a neuroendocrine tumor. PP can be monitored over time alongside Chromogranin A to detect recurrence in patients with resected tumors.

Non-functioning PanNETs
Chromogranin A is the key marker used in diagnosis, treatment monitoring, and recurrence surveillance. While it lacks specificity, consistent trends in Chromogranin A levels can reflect tumor burden and response to therapy.

Conclusion

The Pancreatic Hormone-Secreting Neuro-Endocrine Tumor (PanNET) Panel offers a robust biochemical approach to identifying and managing hormone-producing tumors of the pancreas. By measuring a suite of highly specific hormonal biomarkers, this panel enables the accurate diagnosis of functional PanNETs, assists in clinical decision-making, and supports ongoing monitoring throughout treatment. Given the varied and often severe symptoms associated with these tumors, timely and targeted hormone testing is critical. When interpreted in conjunction with clinical evaluation and imaging, this panel is an indispensable tool in the comprehensive care of patients with neuroendocrine tumors of the pancreas.