Furthermore, brown tumors, especially when manifested on facial bones, can be misdiagnosed as cancerous.

Cysts may be lined by osteoclasts and sometimes blood pigments, which lend to the notion of "brown tumors."

Brown tumours are radiolucent on x-ray.

Brown tumours consist of fibrous tissue, woven bone and supporting vasculature, but no matrix.

The brown tumor is a bone lesion that arises in settings of excess osteoclast activity, such as hyperparathyroidism.

Parathyroidectomy has been shown to result in the reversal of bone resorption and the complete regression of brown tumors.

Additionally, patients with OFC who have undergone parathyroidectomy begin to show regression of brown tumors within six months.

Hemosiderin deposition is not a distinctive feature of brown tumors; it may also be seen giant cell tumors of the bone.

The brown tumors commonly associated with OFC display many of the same characteristics of osteoclasts.

These include, aneurysmal bone cyst, chondroblastoma, simple bone cyst, osteoid osteoma, osteoblastoma, osteosarcoma, giant-cell reparative granuloma, and brown tumor of hyperparathyroidism.

Lu G, Shih WJ, Xiu JY: Technetium-99m MIBI uptake in recurrent parathyroid carcinoma and brown tumors.

The first published literature to describe a brown tumor (which was linked to OFC) was published in 1953, though clinical reports from before 1953 do draw a correlation between the disease and tumors previous to the publication.

In 1884, Davies Colley delivered a presentation to the Pathological Society of London that detailed the manifestation of hyperparathyroidism into a brown tumor of the mandible, as well as the histological makeup of the tumor.

Studies have shown that in cases of OFC caused by either end-stage renal disease or primary hyperparathyoidism, this method is successful not only in treating underlying hyperparathyoidism, but also in causing the regression of brown tumors and other symptoms of OFC.

In addition to elevated blood calcium levels, over-activity of this process results in a loss of bone mass, a weakening of the bones as their calcified supporting structures are replaced with fibrous tissue (peritrabecular fibrosis), and the formation of cyst-like brown tumors in and around the bone.