A 64-year-old investments manager is causing increasing concern to his wife owing to increasing forgetfulness and irritability

A 64-year-old investments manager is causing increasing concern to his wife owing to increasing forgetfulness and irritability. His mother died 3 years previously from Alzheimer’s disease, and his wife is concerned that he is dementing. She had also noticed that he has been drinking more fluid and getting up 2–3 times in the night to pass urine. She persuaded him to see their general practitioner (GP) who found no symptoms of prostatism, and no other relevant past or family history. There was no objective evidence of dementia, and physical examination was normal, including rectal examination. Investigations showed normal urine, fasting blood glucose, urea, creatinine and electrolytes. A wait and see policy was advised with as much reduction in stress as possible and adequate sleep. Over the next 2 months his colleagues begin to question his performance, then one day at work he collapses with severe and sudden-onset left loin pain, radiating down the left flank to his groin and left testicle. The pain is colicky and accompanied by nausea and vomiting. He is taken to the emergency department.
Examination The only physical abnormalities are pallor, sweating, and slight left loin tenderness.
Questions • What is the likely diagnosis? • What other investigations would you perform?

ANSWER
The acute abdominal pain and the haematuria indicate ureteric colic due to a renal stone. The polyuria and polydipsia and the mental changes point to hypercalcaemia causing all three problems. His serum calcium was raised at 3.3mmol/L (normal range: 2.12–2.65mmol/L), corrected for serum albumin concentration, the phosphate was reduced at 0.6mmol/L (normal range: 0.8–1.45mmol/L)) and the alkaline phosphatase raised at 587IU/L (normal range: 30–300IU/L ). This combination of abnormal bone chemistry indicates hyperparathyroidism as the cause of the hypercalcaemia, confirmed by a raised serum parathormone (PTH), and a radio-isotope scan showing a single parathyroid tumour. Other investigations were a renal ultrasound showing a normal urinary tract with no detectable stones. It was assumed that the patient had passed a small stone at the time of the ureteric colic and haematuria. A skeletal X-ray survey was normal, showing no bony metastases and no bony changes of hyperparathyroidism. Hypercalcaemia of any cause can cause polyuria and polydipsia, and can affect mental function. Long-standing hypercalcaemia (therefore not usually in the case of malignancy) also causes renal stones. For some reason primary hyperparathyroidism causes either stones or bone disease, rarely both together.