Primary hyperparathyroidism presenting as an exophytic mandibular mass

A 36-year-old female patient presented with a massive painless swelling in the left mandible. The patient's medical history was unremarkable. The initial clinical and radiological evaluation indicated an aggressive odontogenic neoplasm or a metastasis from an unknown primary; the suspicion of a systemic metabolic or endocrine disorder lay low on the list of differential diagnoses. Further investigations revealed gross skeletal changes and a hypoechoic right parathyroid mass. The total serum parathyroid hormone levels and ultrasound-guided fine needle aspiration cytology (FNAC) of the mandibular and parathyroid lesions provided the diagnosis of primary hyperparathyroidism presenting as a mandibular brown tumour. This case thus highlights the importance of a thorough diagnostic work-up for all lesions in the maxillofacial region and also serves to add another facet to the myriad of presentations associated with primary hyperparathyroidism.