MSRA-0420

MSRA-0420

A 49-year-old woman is admitted to the surgical ward with severe loin to groin abdominal pain. A CT-KUB reveals a right-sided renal calculus. When you take her medical history, she confesses that she has been feeling unwell for the past few weeks with symptoms of polyuria, polydipsia, constipation and altered mood.
Her blood tests show an estimated glomerular filtration rate of >60 ml/min, adjusted calcium of 3.1 mmol/l (2.1-2.6 mmol/l), phosphate of 0.6 mmol/l (0.8-1.4 mol/l), and parathyroid hormone of 5.1 pmol/l (1.2-5.8 pmol/l).
What is the most probable cause of her symptoms?