Mandibular Brown Tumor as Atypical Presentation of Primary Hyperparathyroidism: two Case Reports And Literature Review

Objective: We report 2 cases of patients who developed solitary, aggressive mandibular tumors. The tumors were surgically removed due to suspected malignancy, and their histopathologic diagnoses were central giant cell granuloma and giant cell bone tumor in patients with undiagnosed primary hyperparathyroidism (PHPT).Methods: We present 2 case reports and a review of the literature.Results: Both cases were single, mandibular tumors with aggressive, expansive, and rapidly evolving behavior. In both cases, a malignant tumor process was suspected and the lesion was surgically resected. The histopathologic diagnosis was giant cell bone tumor in one and central giant cell granuloma in the other. Several months later, each was sent to the endocrinology service for hypercalcemia. One of them presented hypercalcemic crisis and pancreatitis and the other had a fractured humerus. The diagnosis of PHPT was made by demonstrating hypercalcemia and elevated parathyroid hormone levels in biochemical studies. The review of the histopathologic study in both cases concluded mandibular brown tumor in the biochemical context of PHPT.Conclusion: The radiologic and histopathologic findings closely resemble each other in these cases. The biochemical diagnosis of PHPT is indispensable for an adequate differential diagnosis and treatment.Abbreviations: HPT hyperparathyroidism PHPT primary hyper-parathyroidism PTH parathyroid hormone