Endocrine Abstracts

Introduction: Islet cells within the pancreas regulate blood glucose through the production of certain hormones, including insulin. Pancreatic neuroendocrine tumours (PNETs) are rare tumours arising from these cells. They are classified as non-functioning (NF-PNET) or functioning (F-PNET). Functional neuroendocrine tumours cause significant symptoms due to the excessive secretion of hormones such as insulin, gastrin, or glucagon. The transformation of NF-PNETs to F-PNETs is a rare occurrence, happening in just 3.4%–6.8% of cases. Patients with metastatic insulinoma, a type of F-PNET, have a poor prognosis, with average survival rates of less than two years.

Case report: We present the case of a 52-year-old male who was admitted to hospital following severe and persistent hypoglycaemic episodes. Insulinoma was confirmed with C-peptide and insulin levels. Prior to diagnosis, he had a five-year history of NF-PNET with liver metastases, which was managed with octreotide, a somatostatin analogue (SSA), and everolimus, a mechanistic target of rapamycin (mTOR) inhibitor. After admission, diazoxide and sunitinib a second-line treatment with palliative intent were started due to the potential wait for peptide receptor radionuclide therapy (PRRT). This is an internal radiotherapy treatment used in symptomatic disease that has metastasised or when surgical excision is not an option. He experienced repeated life-threatening hypoglycaemia and endocrinology advised the use of UKI NETS Bitesize Guidance for the Nutritional Management of Insulinomas. This was implemented by dieticians alongside high-dose IV dextrose. We have outlined the medical challenges over a month, highlighting severe coexistent hyponatremia secondary to the dextrose and arranging PRRT at the nearest nuclear medicine centre. Following transfer the patient was no longer fit for treatment and passed away two weeks later.

Conclusion: PRRT can be difficult to facilitate quickly due to the need for specialist multidisciplinary team (MDT) opinion, octreotide scans, and medical optimization. Reducing local wait times for scintigraphy and obtaining early approval from specialist centres should be a key priority in critical situations. Although this case is extremely rare, it highlights the need for an emergency pathway between regional hospitals for rapid access to treatment. Patients with acute and refractory disease are a subgroup for special consideration.