Resistant hypercalcaemia in metastatic parathyroid carcinoma
We report a case of inoperable metastatic parathyroid carcinoma involving life-threatening hypercalcaemia that failed to respond to standard therapy. Our review of available therapeutic modalities showed a paucity of evidence to guide management of patients with these rare tumours. This is the first report of the treatment of malignant hypercalcaemia secondary to parathyroid carcinoma using denosumab.
A 45-year-old man with no significant past medical history presented with a fractured clavicle and evidence of a radiolucent lesion (brown tumour) within the clavicle on x-ray, characteristic for hyperparathyroidism (Box 1). On further investigation, biochemical analysis showing raised serum calcium and parathyroid hormone (PTH) levels confirmed primary hyperparathyroidism. A thyroid ultrasound showed a 39 × 29 × 32 mm mass in the right lobe, suggestive of a tumour. A staging computed tomography (CT) scan of the neck and chest and a bone scan showed bone changes consistent with hyperparathyroidism throughout the axial and appendicular skeleton. There was no evidence of metastatic disease.