Severe Hypercalcemia from Parathyroid Carcinoma in a Woman on Peritoneal Dialysis

Abstract

Hypercalcemia is rarely a problem found in patients undergoing dialysis. Sometimes it is caused by medicines (vitamin D, calcium phosphate binders), but it could also be caused by disorders such as tertiary hyperparathyroidism or cancers. There is a significant difference in serum calcium levels of patients presenting primary hyperparathyroidism and parathyroid cancer. Patients with primary hyperparathyroidism usually have mild hypercalcemia, while those with parathyroid cancer have much higher serum calcium levels. A dialyzed 69-year-old woman presented with significant hypercalcemia (upper limit 16.6 mg/dl) over the last 3 years, with a gradual increase in serum PTH levels (from 1273-2921 pg/ml). Nodules on the thyroid were found radiologically. Despite our repeated urges for surgical removal of the tumour, the patient was persistently refusing to undergo the operation since May 2015; however, after 3 years, she finally agreed to be operated (May 2018). She underwent total thyroidectomy and parathyroidectomy. One node which was removed was found histologically to have parathyroid cancer. The patient was in good health at 1-year follow-up after removal of the tumour, with normal calcium levels, and subsequently died of cardiac arrest. We present this as a very rare case of severe hypercalcemia due to parathyroid cancer in a patient undergoing peritoneal dialysis.