Severe Thyrotoxicosis: A Rare Cause of Hypercalcemia


S.Qureshi, R.Ratnasabnapathy, S.Stevens, R.Smail, S.Siddiqi, H.Tetlow,K.Ahmed, R.Kaushal,   West Middlesex Hospital.




The pathophysiology of hypercalcemia related to thyrotoxicosis is not fully understood. Milder elevations in serum calcium are observed but significant hypercalcemia is rare. Symptomatic hypercalcemia is an unusual presentation for hyperthyroidism and resolves with treatment of hyperthyroidism. Our case highlights one of the highest levels of calcium reported in patients with thyrotoxicosis.

We present a case of a 29 year old Somalian female, who presented with a three week history of generalized abdominal pain, diarrhoea, vomiting and loss of appetite. On day thirteen of admission it was noted that she had an evident neck swelling, consistent with a thyroid goitre and on assessment of her thyroid status she remained tachycardic, had a marked tremor and thyroid eye signs. Her blood tests were repeated revealing a free T4 >151.9 and TSH <0.04. Her corrected calcium was found to be raised at  3.34 mmol/L.


Following review by the endocrine team she diagnosed with thyrotoxic storm, commenced on carbimazole 80 mg/day, propranolol 240 mg/day, hydrocortisone and aggressively rehydrated. Her calcium remained elevated and therefore was treated with intravenous pamidronate. She remains an inpatient with little resolution of her hypercalcemia, however, is clinically much improved. We await her thyroid antibodies and ultrasound scan report.


Learning Points:

Thyroid function should be checked in all patients who present with hypercalcemia and vice-versa. In such cases, endocrine input should be requested early.


The systemic effects of hypercalcemia can mask the symptoms of thyrotoxicosis risking the development of thyrotoxic storm.