Hypercalcaemia due to primary hyperparathyroidism: variability of symptomatology illustrated by two case presentations.
Nicola M. Neary, Maya Peltsverger, Giao Q. Phan, Electron Kebebew, Stephen Marx and William F. Simonds.
Abstract: Case 1: A 58 year old Mexican female presented to the emergency room with acute confusion and unintelligible speech. She reported bony pain on walking but denied constipation or abdominal pain. Past medical history included depression for which she was treated with mirtazapine. On examination, the mucous membranes were dry. She scored 16/30 on a mini-mental test (MMT) with particular difficulty reproducing interlocking pentagons (Figure). Investigations revealed hypercalcaemia (ionized calcium (iCa) 1.8 (1.12-1.32mmol/l)) with elevated PTH (62.0 (0.3-9.2pmol/l)), low serum phosphorus and elevated 24-hour calcium excretion, consistent with primary hyperparathyroidism (1HPT). She was treated with iv fluids, calcitonin and cinacalcet. The iCa fell to 1.54mmol/l and after 5 days the patientís cognition improved. A sestamibi scan revealed increased uptake on the right side of the neck, confirmed at surgery when a lesion measuring 2.9x2.4x1.8cm was resected. No gross features of parathyroid carcinoma were observed. Intra-operative PTH fell from 186 to 8pmol/l. Pathology showed a few atypical cells (<10 per high power fields) but was thought to be benign with no definitive histological features of carcinoma. The patient remains eucalcaemic with normal serum PTH 18 months post-surgery and is fully orientated and alert.
Case 2: A 64 year old Ethiopian female developed foot pain and was found to be hypercalcaemic. On direct questioning, she reported increased thirst and fatigue. The biochemistry was consistent with 1HPT: iCa 1.8mmol/l, PTH 56.9pmol/l, phosphorus 0.77 (0.81-1.74mmol/l) and elevated 24-h urine calcium. Ultrasound and sestamibi scans indicated a left-sided neck lesion. The patient was fully oriented and scored 30/30 on MMT (Figure). She was rehydrated and given cinacalcet and went on to have left minimally invasive lower parathyroidectomy, at which a 2.5x2.5x1.5cm lesion was removed. Intra-operative PTH fell from 140 to 13pmol/l. Pathology was consistent with a benign adenoma. The patient made a good post-operative recovery and remains eucalcaemic with normal serum PTH 8 months later.
Discussion: These cases illustrate the variability of symptomatology associated with severe hypercalcaemia. Factors explaining the contrasting presentations may include the rate of rise of serum calcium, presence of dehydration, underlying psychiatric disease, and genetic alterations in the proteins comprising the calcium-sensitive ion channel and the calcium-sensing receptor.