Osteitis fibrosa cystica of mandible in hyperparathyroidism-jaw tumor syndrome: A rare presentation and review of literature

Brown's tumor, also referred as osteitis fibrosa cystica is a rare nonneoplastic diagnostically challenging consequence of hyperparathyroidism (HPT) which occurs due to increased parathormone secretions in blood, causing excessive calcium resorption from kidneys, bone resorption, and phosphaturia. Brown's tumor is a misnomer, presenting as cystic expansile lesions in bone, often misdiagnosed as neoplastic lesion or granuloma or abscess in bones. It can affect long bones, clavicle, ribs, and pelvis. According to literature, skeletal manifestations of Brown tumor is relatively rare and occurs in <2% of the cases of HPT. We present a case of a female 15-year-old patient who presented with bleeding gums and an expansile lesion in mandible whose previous investigations elsewhere suggested a malignant lesion. However, further investigations revealed it to be Brown's tumor with primary HPT which is a rare genetic disorder, known as HPT-Jaw Tumor Syndrome (HPT-JT).