Brown tumor causing thoracic compressive myelopathy: A case report and review of literature

Abstract

Brown tumors are nonneoplastic bony lesions resulting from primary, secondary or tertiary hyperparathyroidism. Primary hyperparathyroidism is caused by parathyroid adenomas or parathyroid hyperplasia while chronic renal failure is a common cause of secondary hyperparathyroidism. Elevated parathyroid hormone levels cause increased osteoclastic activity, bone resorption and reactive fibroblastic proliferation leading to the formation of Brown tumor. Although Brown tumors are more commonly seen in the maxilla and mandible, it can occur in the long, flat bones or any bone. It is less commonly seen in the spine. In this report, we discuss the presentation, management, difficulties with histopathological diagnosis, and follow-up of a Brown tumor in a 55-year-old gentleman undergoing renal dialysis who presented with thoracic compressive myelopathy. Our patient underwent a T4 laminectomy, tumor debulking, and T2–T6 instrumented posterior fusion. Based on histopathological examination of the tissue specimen and raised serum parathyroid hormone levels, we arrived at a diagnosis of Brown tumor. Our review of the literature revealed 62 cases of vertebral Brown tumor resulting in neurologic symptoms. The lesion was more common in females (58%), those aged between 40 and 49 years (26%), and in the thoracic spine (51.6%). Early surgical intervention and management of the underlying cause of hyperparathyroidism lead to sustained symptomatic improvement. Brown tumor should be considered in the differential diagnosis of expansile vertebral lesions in the presence of hyperparathyroidism or chronic kidney disease. Treatment of the underlying hyperparathyroidism and decompression of the neural structures with or without stabilization is recommended.