[Multiple maxillofacial brown tumors as primary hyperparathyroidism manifestation].

Objective: In order to analyze the differential diagnosis of giant-cell lesion in facial bones, we present a case of a patient without a previously diagnosed primary hyperparathyroidism that displayed multiple maxillofacial brown tumors as the initial clinical manifestation of the disease.
Case Description: A 70 year-old female with amandible tumor and one year of disease progression. Tumor biopsy confirmed the presence of a giant-cell lesion. Radiologically, we confirmed the presence of another two lytic lesions in the maxillofacial region. During biochemical evaluation prior to surgery, the possibility of hyperparathyroidism was considered. Using computed tomography, we noted a parathyroid tumor in an atypical location. Surgical resection confirmed the presence of an adenoma. Postoperatively, the patient developed symptomatic hypocalcemia and was managed with calcium supplementation in addition to calcitriol. At 4 months after surgery mandibular swelling had regressed partially and serum calcium levels returned to normal levels.
Conclusion: The detection of giant-cell bone lesions in the maxillofacial region is a strategic diagnostic finding as several entities, among these brown tumor hyperparathyroidism can display similar histologic imaging findings. Only systematic clinical, radiologic, and biochemical evaluation can allow for a definitive diagnosis. The presence of multiple simultaneous maxillofacial brown tumors in primary hyperparathyroidism is an infrequent ocurrence, and only on rare occasions can this be the first sign of the disease.