Pancreatic Neuroendocrine Tumour as a Cause of Ectopic Cushing’s Syndrome: A Rare Case Report

Pancreatic Neuroendocrine Tumors (pNETs) are rare neoplasms arising from the neuroendocrine islet cells of the pancreas and account for only 1% to 2% of all pancreatic malignancies. These tumors may secrete hormones; however 60% are considered ‘non-functional’ with no evidence of ectopic hormone secretion. Functional pNETs are known to secrete insulin, gastrin, glucagon, vasoactive intestinal peptide or somatostatin. A small number of the cases reported to date of this condition were typically for patients presenting with Cushing syndrome, where the tumor was discovered during investigations for the source of the ACTH. We report the case of a patient diagnosed with pNET initially believed to be non-functioning, who went on to develop features of ectopic ACTH syndrome (EAS). This case highlights the importance of including cortisol and ACTH levels in screening for neuroendocrine activity in pancreatic tumors. An earlier screening and diagnosis could help ameliorating the patient’s symptoms and halting disease progression.