Endocrine Abstracts

A 70-year old female patient was referred to the Endocrine clinic after incidental finding of significant hypercalcaemia (3.19 mmol/l, NR: 2.20-2.60 mmol/l) during work-up for cognitive decline. She had a known background of T2DM, hyperlipidaemia, osteoarthritis with a previous right total hip replacement and a laparoscopic cholecystectomy. She was first reviewed in clinic in June 2022 and was almost asymptomatic, except for memory issues. She denied previous history of renal calculi and had no fragility fractures in the past. There was no family history of hypercalcaemia or endocrinopathy. On clinical examination, she had a normal blood pressure. There were no palpable neck masses. Screening into end organ complications of hypercalcaemia revealed no nephrolithiasis and the bone density scan (DEXA) showed normal bone density. Calcium-creatinine clearance ratio was 0.02, thereby excluding familial hypocalciuric hypercalcaemia and confirming primary hyperparathyroidism. Parathyroid localisation studies demonstrated a solitary 2.3 cm right superior parathyroid lesion on SPECT-CT. She suffered a rapid decline in cognitive function and was urgently referred for surgical management in view of rising hypercalcaemia. There was an increased risk of hungry bone syndrome in view of significant hypercalcaemia and PTH levels. She was started on vitamin D replacement and cinacalcet titrated to 90 mg twice daily with no significant improvement in her calcium levels which remained persistently above 3.0 mmol/l. She underwent parathyroidectomy in December 2022 with no immediate complications. The histology showed atypical features, including a prominent trabecular growth pattern and fibrous band formation, suggestive of an atypical parathyroid adenoma (APA). She is currently stable with normal calcium levels and will be closely monitored biochemically and radiologically in view of the uncertain malignant potential of APA. Of note, no specific guidelines for the surveillance of patients with APA after parathyroid surgery exist so far.