Brown tumor of the mandible secondary to asymptomatic hyperparathyroidism: a case report

Brown tumor is a rare, non-neoplastic skeletal lesion caused by prolonged hyperparathyroidism (HPT). Its clinical and radiographic mimicry of aggressive bone tumors poses a significant diagnostic challenge. A 46-year-old female was admitted for asthma exacerbation. Routine laboratory tests revealed asymptomatic primary HPT (elevated serum calcium and parathyroid hormone). Subsequently, she developed a painless, expansive mass in the right posterior mandible. Imaging showed an osteolytic lesion with tooth displacement and root resorption. Histopathology confirmed a brown tumor, characterized by multinucleated giant cells, fibrovascular stroma, and hemosiderin deposits. Management involved a two-stage, multidisciplinary approach. The underlying HPT was controlled medically with cinacalcet due to non-localizing parathyroid imaging. The symptomatic mandibular lesion was surgically excised. Recovery was uneventful, with no recurrence at follow-up. The patient was referred for definitive endocrine management and dental rehabilitation. This case underscores that brown tumor can be the initial clinical sign of otherwise asymptomatic HPT. Diagnosis hinges on integrating biochemical, radiographic, and histopathological findings, with careful histological differentiation from other giant-cell lesions. Management requires a tailored strategy, often combining medical control of the metabolic disorder with surgical intervention for local complications. A high index of suspicion and multidisciplinary coordination are crucial for optimal outcomes.