This case highlights an atypical presentation of primary hyperparathyroidism with significant life-threatening hypercalcemia in an 83 year old lady admitted with non-specific symptoms of malaise, dyspnoea and epigastric discomfort. On imaging she was subsequently discovered to have two distinct unexpected findings, a parathyroid mass and a cystic pancreatic mass. Initially an underlying genetic syndrome linking the two structural lesions was considered, possibly a pancreatic neuroendocrine tumor in the presence of a parathyroid mass. However further investigation with a CT pancreatic protocol, revealed her pancreas to show evidence of previous pancreatitis with resultant pseudocyst formation, likely all induced by hypercalcemia of unknown duration. She denied any prior acute episodes of epigastric pain. Whilst previous case reports describe the diagnosis of a parathyroid lesion presenting with acute pancreatitis, our case is rare in that the pancreatitis was an incidental discovery. Although relatively asymptomatic, the pancreatic inflammation induced by hypercalcaemia was significant resulting in development of a large pseudocyst in the pancreatic tail and radiological evidence consistent with previous episodes of pancreatitis. The patient’s hypercalcemia had also resulted in nephrocalcinosis and tooth resorption. This case acts a reminder that although primary hyperparathyroidism is often considered a relatively benign entity, life-threatening hypercalcemia can develop and requires urgent management. It highlights the multi-systemic sequelae that can occur with chronic hypercalcemia and reminds us that parathyroid carcinoma although rare, must always be considered when markedly elevated levels of parathyroid hormone and hypercalcemia are encountered.