Fibrodysplasia: Description, Causes and Risk Factors:Fibrodysplasia is a common benign skeletal lesion that may involve one bone (monostotic) or multiple bones (polyostotic) and occurs throughout the skeleton with a predilection for the long bones, ribs, and craniofacial bones.FibrodysplasiaFibrodysplasia is postulated to occur as a result of a developmental failure in the remodeling of primitive bone to mature lamellar bone and a failure of the bone to realign in response to mechanical stress. Failure of maturation leaves a mass of immature isolated trabeculae enmeshed in dysplastic fibrous tissue that are turning over constantly but never (or very, very slowly) completing the re-modeling process. In addition, the immature matrix does not mineralize normally. The combination of a lack of stress alignment and insufficient mineralization results in substantial loss of mechanical strength, leading to the development of pain, deformity, and pathologic fractures.The etiology has been linked with a mutation in the Gs ? gene that occurs after fertilization in somatic cells and is located at chromosome 20q13.2-13.3. All cells that derive from the mutated cells manifest the dysplastic features. The clinical presentation varies depending on where in the cell mass the mutation is located and the size of the cell mass during embryogenesis when the mutation occurs. Severe disease may be associated with an earlier mutational event that leads to a larger number or a more widespread distribution of mutant cells. The sporadic occurrence of these diseases and the characteristic lateralized pattern of skin and bone involvement in the polyostotic forms of fibrodysplasia suggest this mosaic distribution of abnormal cells. The Gs ? gene has also been linked to other endocrine tumors and human diseases.The pathogenesis of fibrodysplasia involves somatic activating mutation of the gene encoding the alpha subunit of the stimulatory G protein (Gs ?) in the bone marrow cells, resulting in locally increased stimulatory activity of adenyl cyclase and cAMP. This mutation leads to increased production of C-fos protein and interleukin-6 (IL-6) that result in classic dysplastic bone of fibrodysplasia. The associated endocrinopathies are the result of constitutive activation of G protein coupled receptor by hormones acting through it including luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid stimulating hormone (TSH) and growth hormone-releasing hormone (GHRH) thereby manifesting as gonadotropin-independent precocious puberty (GIPP), hyperthyroidism and acromegaly respectively.There is no gender predilection for fibrodysplasia but it is more common in children and adolescents as compared to adults and older patients.Symptoms:The most common presenting manifestations are bone pains, deformity and fractures and sometimes isolated endocrinopathies like GIPP, thyrotoxicosis and acrogigantism. Bone deformity and facial asymmetry were common. Usually patients with monostotic fibrodysplasia have delayed presentation unless accompanied with endocrinopathies as compared to polyostotic variants. Other symptoms include thyroid gland problems and skin discoloration.Diagnosis:The diagnosis of fibrodysplasia is based on classical radiological findings substantiated by bone scans and characteristic pathological findings on histopathology. In some cases, your doctor may order more tests to confirm the diagnosis or to determine the extent of the disorder. They include:Imaging tests. Computerized tomography (CT) or magnetic resonance imaging (MRI) scans may be used to determine how extensively your bones are affected.
  • Bone scan. This test uses radioactive tracers, which are injected into your body. Your bones take up the tracers and emit radiation that's captured by a special camera, which produces a picture of your skeleton. Your doctor may order a bone scan to determine whether your fibrodysplasia is monostotic or polyostotic.
  • Bone biopsy. This test uses a hollow needle to remove a small piece of the affected bone for laboratory analysis. You'll receive local anesthetics to numb the area where the needle is inserted. In rare instances, an open biopsy — requiring general anesthesia and a surgical incision — may be necessary.
Treatment:Till recently, the treatment of fibrodysplasia was only restricted to symptomatic orthopedic management like correction of fractures, internal fixation, curettage and grafting. The use of bisphosphonate (intravenous pamidronate) in fibrodysplasia showed promising results with remarkable improvement in bone pain and healing of bone lesions. Similar effects were later shown by oral alendronate and intravenous zoledronate. The possible mechanism of action of bisphosphonates in fibrodysplasia is related to suppressed osteoclastic activation which occurs in fibrodysplasia due to constitutive activation of Gs ? subunit in the bone tissue.NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.


Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Cart Preview

The 7 Signs Your Body Doesn’t Get Enough Protein

The 7 Signs Your Body Doesn’t Get Enough Protein

Nowadays, everyone knows what protein is but only a few of us know for sure how much of it we need to consume. According to government guidelines, average protein consumption should be 0.8g per kilogram of body weight. The next seven signs show you’re not getting...

Endurance Exercises May Change the Composition of Gut Bacteria

Endurance Exercises May Change the Composition of Gut Bacteria

A new Finnish study, published in the journal Frontiers in Microbiology, finds that endurance exercises may change the composition of gut microbiota. The researchers developed a 6-week program of bicycle training and enrolled 17 overweight women for this program. All...

[WpProQuiz 1]

Featured Products

The 5 Best Accessories for Sports Fans

It is very entertaining to be a sport fan. There is a big variety of sport games that are extremely interesting to follow. Moreover, it is always fun to anticipate the score and watch the enthusiasm live. One of the benefits of being sports fan is using different...

read more

Exercise May Serve as an Antidepressant

A new study of nearly 18,000 participants found that those with high fitness at middle age were significantly less likely to die from heart disease in later life, even if they were diagnosed with depression. Doctor's Tips: How to Stay Fit While Treating Depression Dr....

read more

Fitness: Warm Ups Can Chill Out the Perfomance

The warm ups are supposed to increase body temperature and blood flow so the muscles and surrounding joints become more responsive and prepared for physical activity. Although there’s a neurological element to warm-ups, most research focuses on the physiological...

read more