Primary Hyperparathyroidism Manifested as a Brown Tumor in the Maxilla: Clinical Case Report

Introduction Brown tumor is an uncommon benign bone lesion associated with hyperparathyroidism and excessive osteoclastic activity due to elevated parathyroid hormone levels. It commonly affects long bones and the mandible, while maxillary involvement is uncommon and may mimic other osteolytic or malignant lesions, making diagnosis challenging. Case Report: A 47-year-old woman presented with a four-month history of progressive pain and swelling in the left maxilla, facial asymmetry, and nasal involvement. Imaging revealed an expansive osteolytic lesion in the left maxillary sinus. Laboratory tests demonstrated hypercalcemia and elevated parathyroid hormone levels, consistent with primary hyperparathyroidism. Incisional biopsy showed a giant cell–rich lesion without atypia. Scintigraphy identified a hyperfunctioning parathyroid gland, and parathyroidectomy was performed after metabolic control. Conclusion This case highlights the importance of systemic investigation in patients with expansive maxillary osteolytic lesions, emphasizing the need for integrated clinical, laboratory, and imaging assessment to ensure accurate diagnosis and appropriate management.