Diagnostic and treatment challenge posed by an unusual case of patient with Hypercalcaemia caused by Neuroendocrine tumour.
Sriranganath Akavarapu, P Valsalakumari, J acharya, S Bajwa, J Todd.
Hammersmith Hospital, Imperial College Healthcare NHS Trust
Introduction: Neuroendocrine tumours very rarely cause severe hypercalcaemia and if so commonly by acting through PTH related peptide. We present a case report of severe hypercalcemia caused by neuroendocrine tumour likely due to humoral hypercalcemia of malignancy but with low PTH related protein [PTH rp].
Case Report: A 69 year old male presented with fatigue in May 2014.Blood tests showed corrected calcium of 3.36mmol/L, low phosphate of 0.59mmol/L and elevated Alkaline phosphate of 211 IU/L.PTH was low at 0.2 Pmol/L, myeloma screen was negative and serum ACE levels were normal. Total vitamin D was low at 37nmol/L. CT scan showed 8 cm pancreatic mass with liver secondaries .Biopsy confirmed low grade Neuro endocrine tumour .Gallium scan showed increase uptake in these areas with no bony metastasis.
PTH related protein is undetectable. Over the period of time calcium levels raised up-to 3.8mmol/L with associated symptoms. Despite fluids and octeotride calcium remained high. Although he initially responded to pamidronate the response was transient. He received chemotherapy after MDT discussion and corrected calcium came down to 2.6.
Discussion: Although biochemistry strongly suggested PTH related mechanism with undetectable PTH and low Phosphate suggesting PTH related Protein [PTH rp] might be causing hypercalcemia, In our case biochemical testing for PTH rp is negative. Myeloma screen, Bone scan and ACE levels are normal ruling out other causes. Other potential mechanism is through increased levels of 1, 25 Hydroxy Vitamin –D levels but low phosphate and elevated ALK phosphate are against that.
Conclusion: This case
illustrates diagnostic and therapeutic
challenges posed by hypercalcaemia associated with Neuroendocrine tumour