Endocrine Abstracts

Introduction: Hypercalcemia has wide spectrum of diagnosis. Hyperthyroidism is known cause of parathyroid hormone independent cause of hypercalcemia. Increased osteoclast activity with excess bone resorption is underlying cause. Thyrotoxicosis associated hypercalcemia is usually asymptomatic, mild to moderate hypercalcemia is seen in 20% of patients, but severe hypercalcemia is rare. We report a case of young male who presented with abdominal pain, vomiting secondary to Grave’s disease induced symptomatic severe hypercalcemia.

Clinical Case: 33 year male known case of macroprolactinoma, presented with five days history of abdominal pain, vomiting with on and off palpitations, dizziness but no history of weight loss, kidney stones. He was on cabergoline 500 mg twice weekly. Family history was unremarkable. Examination revealed tachycardia, dry mucous membranes, bilateral gynecomastia and generalized abdominal tenderness. Neck and Testicular examination was normal. Initial investigations showed elevated adjusted calcium of 3.22mmol/l (normal range:2.08–2.80 mmol/l) with suppressed Parathyroid hormone and low Vitamin D, other investigations were normal. Further Investigations ruled out multiple myeloma, granulomatous disease, malignancy. Treatment was initiated with Intravenous hydration followed by intravenous Pamidronate 60mg in accordance with national guidelines for management of hypercalcemia. Due to persistent symptoms of palpitations, abdominal pain, tachycardia, thyroid function tests were performed for suspicion of Thyrotoxicosis. This showed significantly elevated free T4 level, free T3 levels with suppressed thyroid stimulation hormone. TSH receptor antibodies(TRAb) were elevated confirming Grave’s disease. Carbimazole 40mg once a day was initiated. In this case, the main cause of this severe hypercalcemia was considered to be Grave’s disease, other etiolgies were ruled out. His symptoms improved after starting Carbimazole and he was discharged with outpatient follow up with endocrinology department.

Conclusion: This is an atypical presentation of hyperthyroidism-induced symptomatic severe hypercalcemia. Clinicians should be aware of this unusual association, so that a prompt initial evaluation and proper intervention can be administered