Makindo Medical Notes

⚠️ Note: Glucagonomas may be associated with other tumours in Multiple Endocrine Neoplasia type 1 (MEN1), though this is rare (<3% of cases).

📖 About Glucagonoma

• Glucagonoma is a rare pancreatic neuroendocrine tumour arising from α-cells of the islets of Langerhans.
• Often diagnosed at an advanced stage due to subtle early features.
• Most are sporadic, though a minority are linked to MEN1 syndrome.

⚙️ Aetiology

• Slow-growing α-cell tumour producing excessive glucagon → hyperglycaemia & catabolism.
• 80% are malignant at diagnosis.
• Common metastatic sites: liver, lymph nodes, bone, adrenals, kidneys, lungs.

🩺 Clinical Presentation

• Metabolic: Hyperglycaemia, weight loss, diabetes (often mild, non-ketotic).
• Systemic: Glossitis, diarrhoea, anaemia.
• Dermatologic hallmark: Necrolytic Migratory Erythema 🩹 — painful, blistering rash associated with niacin deficiency; often improves with octreotide.
• Thrombosis risk: High rates of DVT/PE due to increased coagulation factors.

🔎 Investigations

• Bloods: FBC, U&E, LFTs, CRP, glucose.
• Hormonal marker: Elevated plasma glucagon.
• Imaging: CT/MRI abdomen → ~50% metastatic at diagnosis.
• Gold standard: Selective visceral angiography (sensitive for primary tumour & liver mets).
• Advanced: Pancreatic venous sampling for glucagon (useful in small/occult lesions).

💊 Management

• Symptomatic control:
  • Octreotide (somatostatin analogue) → suppresses glucagon secretion & improves rash.
  • Niacin supplementation if deficiency confirmed.
• Definitive: Surgical resection = treatment of choice if localized.
• Diabetes management: Often controlled with low-dose insulin (non-ketotic, relatively mild).
• Advanced disease: Debulking surgery, embolisation, or targeted systemic therapies (everolimus, sunitinib, PRRT).

🚨 Clinical Pearls

🔑 Think glucagonoma in weight loss + diabetes + rash (NME).
🧪 Glucagon >500 pg/mL is strongly suggestive.
🩸 Watch for VTE – common and sometimes presenting feature.
🧬 Screen for MEN1 (parathyroid, pituitary, pancreatic tumours) if family history or multiple tumours.

📚 References

• Glucagonoma Syndrome: A Case Report