U010
A reminder of the need for a diagnostic approach to hypercalcaemia.
R Jordon, S K Thukral, J F Todd
Imperial Centre for Endocrinology, Hammersmith Hospital
Abstract:
Primary
hyperparathyroidism should be considered in all patients presenting with hypercalcaemia.
Without appropriate and timely investigation with paired calcium and
parathyroid hormone (PTH) levels, the diagnosis can be overlooked. Furthermore,
bisphosphonates can complicate these investigations as this case reflects.
A 51 year old lady presented to her local
gastroenterology department with a two month history of watery diarrhoea
(bowels opening more than twenty times daily), weight loss and facial flushing.
She was previously fit and well. On examination she was found to be cachectic
with peripheral signs of chronic liver disease and painless hepatomegaly. Stool
cultures were negative. Liver function tests were deranged with a largely
cholestatic picture. A liver ultrasound showed extensive liver metastases. A
subsequent liver biopsy revealed neuroendocrine tumour. Further imaging with
gallium DOTATATE PET-CT showed liver metastases and a likely primary at the
neck of the pancreas, confirmed with endoscopic ultrasound. Fasting gut
hormones showed high vasoactive intestinal peptide (VIP) levels that may be
consistent with a VIPoma.
During the admission at her local hospital, she
developed hypercalcaemia with a calcium level of 3.54 mmol/L. The referring
team treated this with intravenous fluids and two pamidronate infusions. The
PTH level taken after the initial pamidronate infusion when the calcium level
was 3.28 mmol/L and was inappropriately normal at 2.1 pmol/L. A parathyroid
ultrasound showed a possible parathyroid adenoma to be correlated with
sestamibi nuclear imaging. She has been now been referred for multiple
endocrine neoplasia (MEN) genetic screening.
Consideration of MEN was delayed due to failure to diagnose the
underlying cause of hypercalcaemia. This, in part, related to the enthusiastic
use of pamidronate prior to investigation. This caused subsequent difficulty in
interpreting paired calcium and PTH levels. This case highlights the difficulty
in making a diagnosis of primary hyperparathyroidism when hypercalcaemia is
treated without a diagnostic approach.