Refractory paraneoplastic hypercalcaemia responding to cinacalcet

Abstract

A woman in her late 70s presented with an increased frequency of micturition, suprapubic pain and weight loss. She was found to be having advanced cancer of the urinary bladder, coupled with bilateral hydronephrosis.Whilst undergoing surgical intervention for the latter, she was incidentally found to be having hypercalcaemia. This was found to be paraneoplastic in nature, possibly due to elevated parathyroid hormone related peptide with no evidence of bone metastasis. The histology of the resected tumour revealed squamous and sarcomatoid differentiation. Her hypercalcaemia initially responded to intravenous fluids, and later on zolendronate,but the problem recurred again, with the response to a repeat dose of zolendronate and even denosumab being unsatisfactory. As a last resort cinacalcet was started, and although there was a good response to it, our patient sadly died a few weeks later.We believe our case to be the first case of hypercalcaemia associated with isolated bladder cancer which showed a successful response to cinacalcet.