Poster Presentation ESA-SRB-APEG-NZSE 2022
Deterioration in glycaemic control in a patient with a pancreatic mass: a prompt to consider Glucagonoma (#317)
Glucagonoma is a rare functioning pancreatic neuroendocrine tumour (P-NET), with an incidence of 0.01-0.1 per million per year (1). We report a case in a 64-year-old man with a 15-year history of well-controlled type 2 diabetes who presented with significant deterioration in glycaemic control with associated intermittent diarrhoea, weight loss, intermittent aphthous ulceration and a migratory rash.
CT pancreas and 68Ga-DOTATATE PET demonstrated a 20 mm DOTATATE-avid pancreatic tail lesion with 2-3 sub-centimetre DOTATATE-avid lesions in the uncinate process without metastatic disease (Figure 1). Pancreatic polypeptide level was elevated at 759 pmol/L and fasting glucose was 16.2 mmol/L with a markedly increased glucagon level of 508 pg/mL (reference range 40-140), consistent with glucagonoma.
He underwent laparoscopic distal pancreatectomy and splenectomy. Histopathology revealed a 19 mm pancreatic well-differentiated (Grade 1) neuroendocrine tumour with a Ki-67 index of 2%. Immunoperoxidase staining was positive for synaptophysin and glucagon, consistent with a glucagonoma. Glycaemic control improved in the immediate postoperative period with resolution of skin rash and diarrhoea.
Four months postoperatively he required recommencement and rapid uptitration of insulin therapy. The glucagon level decreased to 317 pg/mL one month post operation and 331 pg/mL after six months. Given his ongoing increased insulin requirements, elevated glucagon and remaining pancreatic lesions, endoscopic ultrasound with possible microwave ablation is planned.
First line therapy for locoregionally confined glucagonoma should be surgical resection or radiotherapy ablation where technically feasible. Treatment options for advanced disease include somatostatin analogues, mTOR inhibitors or chemotherapy, with peptide receptor radionuclide therapy emerging as a promising option for metastatic disease (2).
Our case highlights the clinical, biochemical and imaging features of glucagonoma. Poorly controlled diabetes is frequently encountered in clinical practice, thus detailed history of associated symptoms, particularly in patients with pancreatic lesions, may prompt consideration of this rare condition.
Figure 1.
- Falconi M, Eriksson B, Kaltsas G, et al. ENETS Consensus Guidelines Update for the Management of Patients with Functional Pancreatic Neuroendocrine Tumors and Non-Functional Pancreatic Neuroendocrine Tumors. Neuroendocrinology. 2016;103(2):153-171.
- Kindmark H, Sundin A, Granberg D, et al. Endocrine pancreatic tumors with glucagon hypersecretion: a retrospective study of 23 cases during 20 years. Med Oncol. 2007;24(3):330-337.