Endocrine Abstracts

Case history: An 85-year-old man with primary hyperparathyroidism, resistant to cinacalcet, presented to hospital with paranoid delusions, weakness, constipation and thirst. His past medical history was of vitamin D deficiency and arthritis of the spine. Regular medications were lansoprazole, senna, and fluticasone nasal spray. He was a never-smoker and had no relevant family history. Neck examination was unremarkable.

Investigations: Corrected serum calcium (cCa) was initially 4.54 mmol/l, parathyroid hormone (PTH) 104.5 pmol/l, phosphate 0.52 mmol/l, potassium 2.9 mmol/l. 24-hour urinary calcium was 10.1 mmol/dL and calcium:creatinine clearance ratio 2.24. Early morning cortisol was 957 nmol/l, thyroid and liver function were within reference ranges. Initial intravenous fluid therapy lowered cCa to 4.12 mmol/l. A Tc-99m Sestamibi scan identified an oxyphil-rich parathyroid adenoma related to the left upper lobe of the thyroid, later confirmed on ultrasound as a well-defined 17x8x14 mm oval parathyroid lesion with peripheral cystic change.

Results and treatment: : His frailty precluded parathyroidectomy. Management with intravenous fluids, pamidronate, cinacalcet, and denosumab failed to normalise cCa or PTH. Ultrasound-guided ethanol ablation of his parathyroid adenoma was performed. Under local anaesthetic and ultrasound-guidance, a 23-gauge needle was inserted into the parathyroid adenoma and 0.2mls 100% ethanol was injected into the lesion. The procedure was well tolerated with no immediate complications. PTH decreased from 104.5 pmol/l to 24.0 pmol/l and cCa decreased from 3.33 mmol/l to 2.94 mmol/l. The procedure was repeated twice, at 19 and 28 days. Although cCa briefly normalised to 2.49 mmol/l after the third ablation, it returned to a peak of 4.94 mmol/l, and the nadir of PTH was 24.0 pmol/l. The patient died as a result of poor oral intake and hypotension, two months after the first ablation.

Conclusions and points for discussion: Ultrasound-guided ethanol ablation of a parathyroid adenoma is an alternative to surgery in resistant hyperparathyroidism. Results elsewhere showed significant reduction in adenoma size, PTH, and cCa in a comparable patient population (Yazdani, Khalili, Siavash, et al., 2020). This technique carries a relatively small side effect profile and the resources required to perform it are available in district general hospitals. In this case, the procedure was technically successful and showed measurable biochemical improvement. It offered some hope to the patient and his carers, despite events revealing that the improvement was not sustained. The process may help others in this difficult position.