# Glucagonoma

Suspect glucagonoma when necrolytic migratory erythema, weight loss, diabetes, anemia, or thrombosis coexists with marked fasting hyperglucagonemia. Confirm biochemical syndrome, stage with pancreas-protocol imaging and somatostatin receptor PET, obtain graded tissue diagnosis, and prioritize resection when feasible.

**Clinical question:** How should physicians confirm, stage, and manage suspected or established glucagonoma syndrome?

Updated: 2026-09-16T00:18:19.380242+00:00

## What matters in practice
- Order a fasting plasma glucagon concentration when necrolytic migratory erythema, unexplained weight loss, new or worsening diabetes, anemia, glossitis, or characteristic mucocutaneous disease suggests glucagonoma syndrome. [6][12]
- A fasting glucagon level greater than 500 pg/mL is strongly suggestive in the compatible clinical setting; levels above 1,000 pg/mL are diagnostic when glucagonoma syndrome is present. [4][14][20]
- Do not diagnose glucagonoma from mild hyperglucagonemia alone: diabetes, renal or hepatic failure, cirrhosis, sepsis, pancreatitis, trauma, burns, Cushing syndrome, and physiologic stress can elevate glucagon. [6][20][22]
- Stage suspected disease with multiphasic pancreas CT or MRI plus somatostatin receptor PET/CT; obtain biopsy confirmation and Ki-67 grading before systemic treatment when safely feasible. [6][12]
- Refer resectable disease for pancreatic resection with consideration of metastasectomy; unresectable or metastatic disease requires symptom control with a somatostatin analog and multidisciplinary sequencing of NET-directed therapy. [6][8][12]

## When to test for glucagonoma

Test when a characteristic catabolic syndrome is present, not for isolated nonspecific hyperglycemia.

Obtain fasting plasma glucagon in a patient with necrolytic migratory erythema (NME), particularly when accompanied by progressive weight loss, diabetes or glucose intolerance, anemia, glossitis, cheilitis, stomatitis, diarrhea, or venous thrombosis. NME may begin in intertriginous or perineal areas and migrate to the extremities or perioral region; its recognition should prompt biochemical testing even when blood glucose is normal. [4][8][9][12]

Assess immediately for complications that change near-term management: dehydration or clinically important hyperglycemia, severe nutritional decline, anemia, and venous thromboembolism. Thromboembolic events account for more than half of deaths directly attributed to glucagonoma in one summary, supporting a low threshold to evaluate compatible symptoms with venous imaging and to use perioperative deep-vein-thrombosis prophylaxis. [4][20]

Elicit personal and family features of multiple endocrine neoplasia type 1 (MEN1), because approximately one-fifth of glucagonomas are associated with MEN1. In a patient with glucagonoma plus personal or family history suggestive of parathyroid, pituitary, or other pancreatic endocrine tumors, evaluate for a hereditary endocrine syndrome rather than treating the pancreatic lesion as definitively sporadic. [7][8][22]
- High-yield syndrome pattern: NME plus weight loss, diabetes or abnormal glucose tolerance, and anemia. [8][12]
- Important atypical presentation: recurrent stomatitis, glossitis, cheilitis, or migratory painful bullous dermatitis may precede identification of the pancreatic tumor. [4][9]
- Absence of diabetes does not exclude glucagonoma when NME and hyperglucagonemia are present. [9]

*Clinical patterns that should determine whether fasting glucagon testing is pursued. [4][6][8][20]*

| Presentation | Interpretation | Next action |
| --- | --- | --- |
| NME with weight loss, anemia, diabetes, mucositis, or diarrhea [4][8] | High pretest probability of glucagonoma syndrome [6][12] | Obtain fasting plasma glucagon and pancreas-directed staging imaging. [6][12] |
| Marked hyperglucagonemia with compatible syndrome [14][20] | Glucagonoma is likely, especially at concentrations greater than 500 pg/mL. [4][14][20] | Localize and stage with multiphasic CT or MRI plus somatostatin receptor imaging; obtain biopsy for confirmation and grade. [6] |
| Mild glucagon elevation during diabetes, renal failure, cirrhosis, sepsis, pancreatitis, trauma, burns, or stress [6][20][22] | Nonspecific hyperglucagonemia is common and does not establish a functional pancreatic NET. [6][20] | Treat or reassess the confounding condition, repeat fasting testing if suspicion persists, and avoid labeling glucagonoma without clinical and radiologic concordance. [6][20] |
| Very high glucagon without glucagonoma syndrome [20] | Consider familial hyperglucagonemia or Mahvash disease in addition to tumor causes. [20] | Pursue endocrine evaluation and imaging rather than presuming a functioning glucagonoma. [20] |

## Interpret fasting glucagon in clinical context

The diagnosis requires both inappropriate hyperglucagonemia and a compatible functional syndrome or pancreatic NET.

Draw glucagon in the fasting state. A level greater than 500 pg/mL is commonly observed in glucagonoma and is a practical threshold for a strongly suspicious result in the appropriate syndrome; a level greater than 1,000 pg/mL is diagnostic when glucagonoma syndrome is present. Some references define the diagnosis using a greater-than-10-fold elevation above a normal value below 50 pg/mL, underscoring the need to interpret the result against the assay-specific reference range. [4][11][14][20][22]

Do not use glucagon as a stand-alone tumor marker. Mild elevations occur with diabetes mellitus, diabetic ketoacidosis, acute or chronic pancreatitis, renal failure, cirrhosis or chronic hepatic failure, sepsis or bacteremia, Cushing syndrome, acute trauma, burns, portocaval shunting, and other neuroendocrine neoplasms. In these settings, correlate the fasting result with NME or other glucagon-excess manifestations and structural imaging before assigning a glucagonoma diagnosis. [6][20][22]

At the initial biochemical evaluation, document the consequences of hormone excess and nutritional compromise with glucose assessment and HbA1c, complete blood count, albumin, and liver testing. In a patient with a pancreatic NET and symptoms of hormonal excess, fasting assessment of other potentially secreted peptides, including insulin, proinsulin, pancreatic polypeptide, gastrin, VIP, and somatostatin, can identify mixed secretion or an alternative functional pancreatic NET syndrome. [10][11][13][20]
- Diagnostic anchor: fasting glucagon greater than 500 to 1,000 pg/mL with compatible syndrome. [14][20]
- Assay context matters: use the laboratory upper limit of normal when applying a greater-than-10-fold criterion. [11][22]
- Serial glucagon can help follow hormonal activity after treatment, but cross-sectional and receptor imaging determine anatomic disease burden. [4][19]

*Fasting glucagon interpretation and immediate diagnostic consequence. [4][6][14][20][22]*

| Fasting result | Clinical context | Interpretation and action |
| --- | --- | --- |
| Less than 500 pg/mL [20] | No classic syndrome or active confounder [6][20] | Does not support glucagonoma; evaluate alternative causes of rash, weight loss, diabetes, or catabolism. [6][20] |
| Greater than 500 pg/mL [4][14][20] | NME or other characteristic glucagon-excess features [6][10] | Strongly suspect glucagonoma; proceed to pancreas-protocol CT or MRI and somatostatin receptor imaging. [6] |
| Greater than 1,000 pg/mL [20] | Glucagonoma syndrome present [20] | Diagnostic of glucagonoma in this clinical setting; stage disease and obtain tissue for NET confirmation and Ki-67 grade. [6][20] |
| Very high concentration [20] | No functional syndrome [20] | Broaden differential to familial hyperglucagonemia and Mahvash disease while evaluating for a pancreatic lesion. [20] |

## Localize the primary and define resectability

Use anatomic imaging for operative anatomy and receptor imaging for metastatic mapping and treatment selection.

Perform multiphasic, three-phase CT or MRI of the pancreas for primary-tumor localization and liver staging. Glucagonomas are usually pancreatic, frequently arise in the distal pancreas, and are often large at diagnosis; contrast-enhanced CT commonly demonstrates a hypervascular pancreatic lesion and can identify hypervascular liver metastases. [6][19][22][23]

Add somatostatin receptor imaging, preferably PET/CT with gallium-68-labeled DOTATATE, DOTANOC, or DOTATOC, to define receptor-positive metastatic disease. These PET techniques have the highest sensitivity for metastases from grade 1 to 2 and some grade 3 pancreatic NETs; somatostatin receptor scan positivity has been reported in up to 97% of glucagonoma patients. If PET is unavailable, indium-111 pentetreotide SPECT/CT can demonstrate receptor expression, although it is an older modality. [5][6][10][11]

Obtain core biopsy of a metastatic lesion or primary tumor when tissue will establish diagnosis, determine differentiation, and provide Ki-67 grading before systemic therapy. Expected supportive immunophenotype in a well-differentiated glucagonoma includes neuroendocrine-marker positivity such as chromogranin and synaptophysin with glucagon positivity; pathology should distinguish well-differentiated pancreatic NET from poorly differentiated neuroendocrine carcinoma because treatment strategy differs. [5][6][23]

Translate staging into a resectability decision in a pancreatic NET multidisciplinary setting. Localized pancreatic disease is potentially curable with surgery. For liver involvement, hepatic resection is considered when liver disease is not widespread, extrahepatic disease is not diffuse, and liver function is adequate; diffuse metastatic disease instead requires disease-control and symptom-control planning. [8]
- Use CT or MRI to map pancreatic and hepatic anatomy for surgical planning. [6]
- Use somatostatin receptor PET/CT to identify receptor-positive disease and potential eligibility for receptor-directed therapy. [6][12][15]
- Use biopsy for diagnostic confirmation and Ki-67 grading, especially before initiating systemic treatment for unresectable or metastatic disease. [6]

*Imaging and tissue studies by decision they inform. [5][6][8][12]*

| Study | Primary decision | Actionable finding |
| --- | --- | --- |
| Three-phase pancreatic CT or MRI [6] | Primary localization and surgical anatomy | Defines pancreatic lesion, vascular relationships, hepatic burden, and operative planning. [6][23] |
| Gallium-68 somatostatin receptor PET/CT [6] | Whole-body receptor-positive staging | Maps metastatic receptor-positive disease and supports selection of somatostatin analog or PRRT-based strategy. [6][12][15] |
| Indium-111 pentetreotide SPECT/CT [5][11] | Alternative receptor imaging | Demonstrates somatostatin receptor expression in pancreatic and metastatic lesions when used with anatomic imaging. [5][11] |
| Core biopsy with morphology, neuroendocrine markers, glucagon staining, and Ki-67 [5][6][23] | Diagnostic confirmation and grade | Confirms pancreatic NET phenotype and provides grade needed for systemic-treatment planning. [6][23] |

## Treat the catabolic syndrome while staging proceeds

Control metabolic, nutritional, dermatologic, and thrombotic complications in parallel with tumor-directed planning.

Address hyperglycemia according to its severity while recognizing that successful suppression or removal of glucagon-secreting tumor can improve glucose control. Monitor glucose and HbA1c during treatment because somatostatin analogs suppress hormone secretion but may also affect insulin secretion; treatment response should be judged by symptoms and glycemic trajectory as well as glucagon concentration. [13][20]

Treat NME and catabolic decline as manifestations of hormone excess and nutritional compromise rather than as isolated dermatitis. Initiate nutritional assessment and repletion in patients with weight loss, hypoalbuminemia, mucositis, or severe cutaneous disease; preoperative nutrition support is specifically reported as part of multidisciplinary glucagonoma management. NME often improves when glucagon levels decline after tumor resection, cytoreduction, or somatostatin analog therapy. [10][13][20]

Maintain heightened vigilance for venous thromboembolism. Obtain diagnostic testing for new dyspnea, chest pain, unilateral limb symptoms, or otherwise unexplained clinical deterioration, and use routine perioperative deep-vein-thrombosis prophylaxis when surgery is undertaken. [4][20]
- Monitor: glucose, HbA1c, weight trajectory, complete blood count, albumin, liver tests, fasting glucagon, and NME severity. [4][13][19]
- Escalate metabolic and nutritional support before major surgery when weight loss, hypoalbuminemia, or extensive NME indicates a catabolic state. [10][20]
- Do not defer tumor localization because isolated dermatologic treatment does not address glucagon excess. [9][24]

## Choose surgery first when complete or meaningful cytoreduction is feasible

Treatment selection depends on resectability, hepatic distribution, tumor grade, receptor expression, symptoms, and pace of progression.

Refer localized glucagonoma for pancreatic resection because surgery is the only potentially curative treatment. Resection type is determined by tumor location. In patients without metastases, surgery alone has been associated with postoperative 5-year survival greater than 85%; resection also reduces glucagon concentration and can substantially improve NME. [4][8]

For selected hepatic metastases, consider combined or staged resection of the primary and liver metastases when disease is not widespread, diffuse extrahepatic metastases are absent, and hepatic functional reserve is adequate. Cytoreductive surgery can reduce tumor burden and glucagon levels, but it is not equivalent to cure in disseminated disease; preoperative nutritional optimization and thrombosis prophylaxis are important perioperative components. [8][20]

For unresectable, locally advanced, or metastatic receptor-positive glucagonoma, use a somatostatin analog as first-line hormone-control therapy and as part of tumor-control management. Somatostatin analogs suppress glucagon secretion and are associated with improvement in NME and other glucagonoma-syndrome manifestations. Specific agent selection and dose should follow current pancreatic NET labeling and multidisciplinary guidance because glucagonoma-specific dosing data are limited. [6][12][13][20]

If disease progresses or tumor burden requires additional control, select therapy by differentiation, Ki-67 grade, disease tempo, somatostatin receptor expression, prior treatment, and patient comorbidity. Guideline-based pancreatic NET sequencing includes targeted therapy, peptide receptor radionuclide therapy with radiolabeled somatostatin analogs for receptor-positive disease, and cytotoxic chemotherapy for clinically high disease burden. Everolimus and sunitinib are indicated to improve progression-free survival in progressing pancreatic NETs; lutetium-177 DOTATATE is an option for somatostatin receptor-positive gastroenteropancreatic NETs. [6][15]

Use PRRT only after confirming somatostatin receptor positivity and coordinating care through an experienced NET team. Cohort evidence in receptor-positive glucagonomas suggests lutetium-177 DOTATATE may improve disease and symptom control, but direct glucagonoma-specific comparative data remain limited. [6][12]
- Localized primary: pancreatic resection with curative intent. [8]
- Limited resectable hepatic disease: evaluate for metastasectomy when liver function and extrahepatic disease distribution permit. [8]
- Unresectable receptor-positive functional disease: somatostatin analog for hormonal symptom control and tumor stabilization. [6][12][13]
- Progressive pancreatic NET: consider everolimus, sunitinib, PRRT for receptor-positive disease, or cytotoxic chemotherapy for high burden in multidisciplinary review. [6][15]

### Follow-up after treatment

Monitor clinical response with NME activity, weight, glycemic measures, anemia and nutritional indices, plus fasting glucagon when initially elevated. Use serial CT or MRI to assess anatomic progression and apply RECIST-based radiologic response assessment in patients receiving systemic treatment; receptor imaging is particularly useful for initial metastatic mapping and may inform subsequent receptor-directed treatment decisions. [4][12][19]
- After resection, falling glucagon and resolution of NME support biochemical and clinical response; persistent elevation should prompt reassessment for residual or metastatic disease. [8][19]
- During advanced-disease treatment, distinguish symptom progression from radiographic progression and reassess receptor status and tumor grade when treatment resistance changes the management pathway. [6][12]

*Treatment selection for glucagonoma by disease distribution and biology. [6][8][12][15][20]*

| Clinical state | Preferred treatment direction | Key selection constraint |
| --- | --- | --- |
| Localized resectable pancreatic glucagonoma [8] | Pancreatic resection with curative intent [8] | Procedure is determined by pancreatic location and operative anatomy. [8] |
| Limited resectable liver metastases [8] | Consider hepatic resection or metastasectomy with primary-tumor surgery [8] | Avoid when liver involvement is widespread, extrahepatic disease is diffuse, or hepatic function is inadequate. [8] |
| Unresectable or metastatic functioning disease [6][12] | Somatostatin analog for glucagon suppression, syndrome control, and tumor stabilization [6][13] | Confirm clinically meaningful glucagonoma syndrome and assess somatostatin receptor expression. [6][12] |
| Progressive receptor-positive metastatic pancreatic NET [6][15] | Consider lutetium-177 DOTATATE PRRT in an NET multidisciplinary program [6][15] | Requires somatostatin receptor-positive disease. [6][15] |
| Progressive pancreatic NET or high disease burden [6][15] | Consider everolimus, sunitinib, or cytotoxic chemotherapy according to disease behavior [6][15] | Choose according to grade, pace, burden, prior therapy, and patient-specific risk. [6][15] |

## Common questions

### Does a normal glucose level exclude glucagonoma?

No. A reported glucagonoma case with characteristic NME, weight loss, and elevated glucagon had normal blood glucose; test fasting glucagon when the dermatologic and catabolic syndrome is convincing. [9]

### What should prompt reassessment after apparent dermatologic treatment failure?

Persistent or recurrent NME with stomatitis, glossitis, weight loss, anemia, or evolving glucose intolerance should trigger fasting glucagon testing and pancreas-directed imaging rather than repeated treatment as isolated inflammatory dermatitis. [9][12][24]

## References
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2. Cystic glucagonoma: a rare variant of an uncommon neuroendocrine pancreas tumor - ScienceDirect — www.sciencedirect.com — https://www.sciencedirect.com/science/article/abs/pii/S1091255X9880053X
3. A familial glucagonoma syndrome: Genetic, Clinical and Biochemical Features - ScienceDirect — www.sciencedirect.com — https://www.sciencedirect.com/science/article/abs/pii/0002934381908585
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15. [PDF] P R O T O C O L C O V E R P A G E - ClinicalTrials.gov — cdn.clinicaltrials.gov — https://cdn.clinicaltrials.gov/large-docs/37/NCT02549937/Prot_000.pdf
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## Editorial note

Prepared from cited clinical literature using Astra's research workflow. Verify recommendations against current guidance and patient-specific factors.