Brown Tumor Related to Primary Hyperparathyroidism Mimicking Malignity in the Mandible: Case Report and Literature Review

Brown tumors can be found in any bone, during the course of primary hyperparathyroidism and may be misdiagnosed as tumors of bone origin. In this case report, we emphasized the importance of considering primary hyperparathyroidism in the differential diagnosis of a patient who presented with a mass in the mandible and was thought to have a malignant mass lesion originating from the mandible on tomography. A 27-year-old male patient applied to an external center due to enlarge-ment of the left jaw and swelling in the mouth, which started 2 months ago and increased over time. Based on the biopsy and mandibular tomography results taken from the intraoral lesion, he was referred to our hospital from the external center for excision, considering a bone orginated malignant mass in the mandible. Laboratory examinations of the patient revealed a calcium serum level of 13.6 mg/dL and the parathyroid hormone level of 508 ng/L. In parathyroid ultrasonogra-phy, hypoechoic nodular formation adjacent to the thyroid capsule on the left inferior posterior, was evaluated as a parathyroid adenoma. Histopathological diagnosis from parathyroid ademocectomy, and the the mandibular mass , revealed a parathyroid adenoma and brown tumour respectively. We have compiled 5 cases in the literature, initially thought to be malignant bone tumors but later turned out to be brown tumors due to primary hyperparathyroidism. Increasing surgeons' awareness about primary hyperparathyroidism is important as patients with brown tumors are first admitted to surgeons. Considering primary hyperparathyroidism in masses of bone origin avoids unnecessary surgeries.