Multifocal osteolytic lesions of jaw as a road map to diagnosis of brown tumor of hyperparathyroidism: A rare case report with review of literature.

Brown tumor is unifocal or multifocal bone disease which represents terminal stage of hyperparathyroidism (HPT)-dependent bone pathology. It is recognized as a component of metabolic bone disease called osteitis fibrosa cystica generalisata or Von Recklinghausen disease of bone. HPT was first described by Von Recklinghausen in 1891. Brown tumor diagnosis nowadays is less frequently encountered because of early stage detection of HPT. This early detection is possible due to routine blood screening in asymptomatic adults or during evaluation of osteoporosis. Histologically, it may resemble any other giant cell lesion of the jaw that imposes diagnostic challenge and delay in treatment. We are introducing a case report of a 30-year-old female patient presented with multifocal osteolytic lesions in mandible with histopathology depictive of giant cell granuloma. Further biochemical investigations and X-ray skeletal changes raised the suspicion of primary HPT which was confirmed by parathyroid scintigraphy revealing parathyroid adenoma. The main purpose of this case report is to reinforce the role of oral examination in diagnosis of systemic diseases and to propose a diagnostic layout/algorithm when giant cells are present in biopsy specimen. Review of literature showing brown tumor of oral cavity associated with PHPT is discussed.