[Primary hyperparathyroidism and acute toxic hypercalcaemic crisis]

To describe the clinical characteristics and surgical treatment of patients with acute hypercalcaemia due to primary hyperparathyroidism (PHPT) and compare them with other patients with PHPT without associated acute hypercalcaemia.

A prospective, observational study (1998-2010) was conducted on 158 patients with PHPT treated by parathyroidectomy. Those with acute hypercalcaemia (>14 mg/dl -3.5 mmol/L- or >3 mmol/L with symptoms of calcium toxicity) were evaluated by recording their clinical and treatment characteristics, and comparing them, using the Mann-Whitney U test and the Fisher test, with the 146 PHPT patients without hypercalcaemic crisis.

Twelve patients (7.6%) had acute hypercalcaemia with symptoms of calcium toxicity and other symptoms of chronicity. The preoperative calcium and PTH values were 14.5 ± 1.3mg/dL and 648.2 ± 542 pg/dL, respectively. There were 10 adenomas, 1 hyperplasia and 1 carcinoma. The mean weight of the surgical pieces was 4.075 ± 2.918 mg, with a diameter greater than 27 ± 14 mm. The gradients of PTH at 10 and 25 minutes were 79 ± 18% and 92 ± 6%, respectively. Post-operative calcium values on discharge and at 6 months were 8.2 ± 0.7 mg/dL and 9.1 ± 0.9 mg/dL, respectively. The plasma concentrations of calcium, PTH, and the size of the surgical pieces were higher in patients with hypercalcaemic crisis (P<0.001). There were no differences in the other parameters studied or in the cure rate.

Hypercalcaemic crises were caused by larger and heavier tumours that led to higher plasma Ca and PTH plasma concentrations. All patients had long-standing symptoms and parathyroidectomy led to cure of the disease.