Endocrine Abstracts

We present the case of an elderly man who was referred by his GP for hypercalcaemia. The patient had a preexisting large right-sided thyroid swelling but no other significant medical history. Blood tests revealed high calcium levels and significantly elevated levels of parathyroid hormone (PTH), which is unusual in a typical case of primary hyperparathyroidism secondary to parathyroid adenoma. The biochemical findings raised suspicion towards a diagnosis of parathyroid carcinoma. He was initially treated with intravenous Zoledronic acid and fluids. However, his calcium levels remained persistently high. Next cinacalcet therapy was initiated, the dosage of cinacalcet was gradually increased up to the maximum. Despite maximum pharmacological treatment, calcium, and PTH levels remained persistently elevated. (calcium 3.28 and PTH 90.9). These biochemical results favoured a carcinoma rather than an adenoma. However confirming the diagnosis was a challenge, both nuclear and CT scans, typically instrumental in identifying such conditions, showed an 8.9 cm cystic mass in the thyroid. However, an FNAC which was done failed to provide conclusive evidence. The case was discussed with ENT and the decision was made for emergency surgery. The surgery included a right hemithyroidectomy, parathyroidectomy, and excision of the cyst. Surgery was the definitive treatment for this gentleman, addressing both his compressive symptoms and reducing his calcium and PTH levels. Cystic parathyroid adenomas exhibit varying clinical presentations, from mild symptomatic hyperparathyroidism, where patients experience fatigue or weakness to more serious presentations such as hypercalcaemic crisis or compression of surrounding structures. Parathyroid cysts can also be incidentally discovered. This diversity in clinical presentation underscores the importance of cystic parathyroid adenoma as a potential differential diagnosis in patients presenting with hyperparathyroidism or neck masses. It is also important to differentiate parathyroid adenoma from cystic lesions since they can lead to severe hypercalcaemic crises and their risk of malignant transformation.