Osteitis fibrosa cystica

Osteitis fibrosa cystica

Osteitis fibrosa cystica of the tibia. Arrows point to the brown tumors which are typically present in bones of people with OFC.
Classification and external resources
Specialty	endocrinology
ICD-10	E21.0
ICD-9-CM	252.01
OMIM	603233
DiseasesDB	30721
MedlinePlus	001252
MeSH	D010002
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Osteitis fibrosa cystica (/ˌɒstiˈaɪtᵻs faɪˈbroʊsə ˈsɪstᵻkə/ OS-ti-AY-təs fy-BROH-sə SIS-tə-kə), is a skeletal disorder resulting 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. Osteitis fibrosis cystica, abbreviated OFC, also known as osteitis fibrosa, osteodystrophia fibrosa, and Von Recklinghausen's disease of bone (not to be confused with Von Recklinghausen's disease, neurofibromatosis type I), is caused by hyperparathyroidism, which is a surplus of parathyroid hormone from over-active parathyroid glands. This surplus stimulates the activity of osteoclasts, cells that break down bone, in a process known as osteoclastic bone resorption. The hyperparathyroidism can be triggered by a parathyroid adenoma, hereditary factors, parathyroid carcinoma, or renal osteodystrophy. Osteoclastic bone resorption releases minerals, including calcium, from the bone into the bloodstream, causing both elevated blood calcium levels, and the structural changes which weaken the bone. The symptoms of the disease are the consequences of both the general softening of the bones and the excess calcium in the blood, and include bone fractures, kidney stones, nausea, moth-eaten appearance in the bones, appetite loss, and weight loss.