Endocrine Abstracts

A 72 year old lady presented to Endocrinology in 2001 with primary hyperparathyroidism and had a parathyroid adenoma resected, resulting in normocalcaemia. In 2006, she developed mild hypercalcaemia (2.61-2.71 mmol/l) and underwent extensive investigations for recurrent PHPT. Parathyroid localization studies, including FDG PET, failed to identify any adenoma. The patient declined bilateral neck exploration and she was managed conservatively. A DEXA scan showed evidence of osteoporosis at the spine (T score -2.9) and normal bone mineral density (BMD, T score -1.0) at the hip. She was treated with annual IV zoledronic acid for five years. During this time, her serum calcium normalized, and she was discharged to primary care in 2011. In 2021, she was re-referred to secondary care with persistent hypercalcaemia (~2.67 mmol/l). A renal tract ultrasound showed no evidence of nephrocalcinosis. There was no history of fragility fracture. A repeat DEXA scan showed a T-score of -1.9 at the spine, -1.3 at the hip and -4.2 at the left radius. Her FRAX score revealed a 10-year probability of a major osteoporotic fracture at 16% and that of a hip fracture at 3.6%. With regards to other risk factors for osteoporosis, she stopped smoking 2 years ago, after having been a lifelong smoker. She has a BMI of 23.67 kg/m2. She was recently diagnosed with seropositive rheumatoid arthritis (RA) and is on treatment with methotrexate. She is awaiting knee replacement surgery for osteoarthritis (OA). She also has a known background of upper lobe lung fibrosis secondary to previous pneumonia. Her regular medications include methotrexate, folic acid, sulfasalazine and morphine sulphate. She receives regular intra-articular glucocorticoid injections for OA. Due to frequent flares of RA requiring courses of oral glucocorticoids, treatment with biologics is being consideredQuestions:

1. A T-score of -4.2 at the radius in the context of PHPT is an indication for parathyroidectomy. Other risk factors for low wrist BMD could be RA and GC use. Is there a need for surgery if previous investigations failed to localize any adenoma and the patient is not keen on neck exploration?

2. As per the FRAX score, treatment for osteoporosis is not indicated as per NOGG 3. In patients with PHPT with osteoporosis who do not undergo surgery, denosumab is considered. However, our patient is not a candidate because of i) lung fibrosis and ii) biologics therapy for RA. Denosumab is also unlikely to reverse low radius BMD