Refractory hyperparathyroidism with a T3 bony lesion—differential diagnoses

We report a case of severe hyperparathyroidism complicated by osteitis fibrosa cystica in an 83-year-old man post-myocardial infarction. The lesions were evident on magnetic resonance imaging only. A diagnosis of parathyroid carcinoma was considered due to clinical appearance of the parathyroid intraoperatively and the presence of an invasive T3 lesion mimicking metastatic disease. Differentiating parathyroid carcinoma from the benign causes at presentation can be difficult due to overlapping clinical, biochemical, radiological and histological features. The presence of bony lesions increases the diagnostic complexity of the case and demonstrates the challenges involved in the management of this disorder.