An unusual cause of life-threatening hypercalcaemia treated with haemodialysis
Panos Thefanoyiannis, Vooi Lee Loh & Leighton J Seal
We present a case of a 71-year-old Jamaican man who presented with a 4 weeks history of backache, lethargy, night sweats, decreased appetite, and weight loss. There was no significant medical history.
Physical examination revealed tachypnoea, sinus tachycardia with evidence of short QT interval on the ECG, generalised lymphadenopathy with firm, rubbery glands up to 3×3 cm in diameter. Arterial blood gases were consistent with type 1 respiratory failure.
His blood tests showed corrected calcium of 4.78 mmol/l, phosphate 1.60 mmol/l, urea 22.6 mmol/l, creatinine 142 μmol/l, PTH <0.7 pmol/l (NR 1.16.9), and PTHrP level was about 10-fold higher (10.0 pmol/l) than the upper normal limit with no paraprotein detected.
A CT scan of the brain, thorax and abdomen revealed pulmonary embolism, widespread lymphadenopathy with multiple lytic lesions within the bones including the skull vault suggestive of a lymphoproliferative process. Lymph node biopsy confirmed a diagnosis of adult T-cell lymphoma.
He was rehydrated aggressively with crystalloids; in addition, he was treated with furosemide, calcitonin, bisphosphonates and steroids.
The corrected calcium did not improve after initial treatment and due to worsening confusion, a decision was made to give him a short course of hemodialysis, which resulted in marked biochemical (Ca 2.87 mmol/l) and clinical improvement.
The human T cell lymphotrophic virus (HTLV) type 1/2 antibody was positive.
Adult T-cell leukaemia/lymphoma is an aggressive and often fatal malignancy of CD4 T-cells caused by infection with HTLV-1. HTLV-1 infection is endemic in Japan, the Caribbean and parts of Africa.
The mechanism for hypercalcemia has been described as increased bone resorption mediated by PTHrP or lymphokines, such as interleukin 1 (IL-1), IL-2, IL-6, and tumour necrosis factor.
There are currently no guidelines for the treatment of hypercalcaemia associated with malignancy. In cases of resistant, life-threatening hypercalcaemia, haemodialysis is effective and may reduce mortality.