To report a rare case of axis brown tumor and to review literature of cervical spine brown tumor. Brown tumor is a rare bone lesion, incidence less than 5% in primary hyperparathyroidism. It is more common in secondary hyperparathyroidism with up to 13% of cases. Brown tumor reactive lesion forms as a result of disturbed bone remodeling due to long standing increase in parathyroid hormones. Cervical spine involvement is extremely rare, can be confused with serous spine lesions. To date, only four cases of cervical spine involvement have been reported. Three were due to secondary hyperparathyroidism. Only one was reported to involve the axis and was due to secondary hyperparathyroidism. This is the first reported case of axis brown tumor due to primary hyperparathyroidism. A case report of brown tumor is presented. A literature review was conducted by a Medline search of reported cases of brown tumor, key words: brown tumor, osteoclastoma and cervical lesions. The resulting papers were reviewed and cervical spine cases were listed then classified according to the level, cause, and management. Only four previous cases involved the cervical spine. Three were caused by secondary hyperparathyroidism and one was by primary hyperparathyroidism which involved the C6. Our case was the first case of C2 involvement of primary hyperparathyroidism and it was managed conservatively. Brown tumor, a rare spinal tumor that presents with high PTH and giant cells, requires a high level of suspicion.
Keywords: Axis neoplasm; Brown tumor; Hyperparathyroidism; Osteitis fibrosa cystica; Osteoclastoma.