Fibrous dysplasia

Fibrous dysplasia is a developmental disorder of bone that can present in a monostotic or polyostotic form. Primarily affecting adolescents and young adults, it accounts for 7% of benign bone tumors. Many of the asymptomatic lesions are found incidentally; the remainder present with symptoms of swelling, deformity, or pain. Fibrous dysplasia has been associated with multiple endocrine and nonendocrine disorders and with McCune-Albright and Mazabraud's syndromes. The etiology remains unclear, but molecular biology suggests a mutation in the G(s)alpha subunit and activation of c-fos and other proto-oncogenes. Fibrous dysplasia has a characteristic radiographic appearance. Most cases do not require intervention, but those that do usually are managed surgically with curettage, bone grafting, and, in some cases, internal fixation. When some intervention is necessary but surgery is not practical, treatment is with bisphosphonates. The prognosis generally is good, although poor outcomes are more frequent in younger patients and in those with polyostotic forms of the disease. The risk of malignant transformation is low.     

Fibrous dysplasia.

The controversy is this case centers around the management of this lesion, not the differential diagnosis. All the consultants agreed that the history, physical, and CT findings were consistent with various fibroosseous lesions, the most likely being fibrous dysplasia. The need for additional tests varied with a bone scan (Dr. Kearns), a bone scan and CT scan (Dr. McGill), and MRI, MRI angiogram, bone survey, BUN, creatinine, calcium, and phosphorus (Dr. Potsic). Cosmetic and functional changes were considered priorities for the consultants, with orbital compression, malocclusion, tooth eruption, nasal obstruction, and sinusitis (Dr. Kearns), nasolacrimal duct obstruction and orbital compression (Drs. McGill and Potsic) being the concerns. Because this lesion is benign and slow-growing, the consensus is that surgery should be reserved for functional or cosmetic compromise. But how aggressive should one be and what approach should be used? The approaches varied with midface degloving or lateral rhinotomy (Dr. Kearns), midface degloving (Dr. McGill), or a Caldwell-luc and lateral rhinotomy (Dr. Potsic). Assessment of this tumor postoperatively should be with patient examinations and serial CT scans. None of the consultants worried about sarcomatous changes in this tumor.     

Fibrous dysplasia and cherubism

Fibrous dysplasia (FD) is a non-malignant fibro-osseous bony lesion in which the involved bone/bones gradually get converted into expanding cystic and fibrous tissue. The underlying defect in FD is post-natal mutation of GNAS1 gene, which leads to the proliferation and activation of undifferentiated mesenchymal cells arresting the bone development in woven phase and ultimately converting them into fibro-osseous cystic tissue. Cherubism is a hereditary form of fibrous dysplasia in which the causative factor is transmission of autosomal dominant SH3BP2 gene mutation. The disease may present in two distinct forms, a less severe and limited monostotic form, and a more aggressive and more widespread polyostotic form. Polyostotic form may be associated with various endocrine abnormalities, which require active management apart from the management of FD. Management of FD is not free from controversies. While total surgical excision of the involved area and reconstruction using newer micro-vascular technique is the only definitive treatment available from the curative point of view, but this can be only offered to monostotic and very few polyostotic lesions. In polyostotic varieties on many occasions these radical surgeries are very deforming in these slow growing lesions and so their indication is highly debated. The treatment of cranio-facial fibrous dysplasia should be highly individualized, depending on the fact that the clinical behavior of lesion is variable at various ages and in individual patients. A more conservative approach in the form of aesthetic recontouring of deformed bone, orthodontic occlusal correction, and watchful expectancy may be the more accepted form of treatment in young patients. Newer generation real-time imaging guidance during recontouring surgery adds to accuracy and safety of these procedures. Regular clinical and radiological follow up is required to watch for quiescence, regression or reactivation of the disease process. Patients must be warned and watched for any sign of nerve compression, especially visual impairment due to optic nerve compression. Rather than going for prophylactic optic canal decompression (which does more harm than good), optic nerve decompression should be done in symptomatic patients only, and preferably be done via minimal invasive endoscopic neuro-surgical approach than the conventional more morbid open craniotomy approach. There is growing research and possibilities that newer generation bisphosphonate medication may change the management scenario, as these medications show encouraging response in not only reducing the osteoclastic activity, but simultaneously also stimulating the osteoblastic and osteocytic activities. The explosion of genetic research and stem cell therapy may lead to better understanding and subsequently better treatment of FD in future.KEY WORDS: Bisphosphonate, cherubism, cranio-facial fibrous dysplasia, fibro-osseous bony lesion, fibrous dysplasia     

Fibrous dysplasia of the clivus

OBJECTIVE: Fibrous dysplasia is a developmental skeletal disorder that may lead to distortion, expansion, and weakening of the bone. Craniofacial involvement by this entity is well recognized and is known to cause neurovascular impingement and cosmetic deformity; fibrous dysplasia of the clivus, however, is unrecognized and seldom reported. Differentiating this entity from more aggressive disease processes affecting the clivus is central for the proper management of lesions in this area. We have studied fibrous dysplasia of the clivus with the goal of depicting its manifestations, outlining its management, and heightening awareness of this disease entity. METHODS: We retrospectively reviewed our database and identified patients with the diagnosis of fibrous dysplasia of the clivus. The demographic data, the clinical and radiological findings, and the management of these patients were reviewed. RESULTS: Eight patients who had experienced fibrous dysplasia of the clivus were identified. They either were asymptomatic (four patients) or presented with headache (four patients). Of the patients who presented with headache, one also had XIIth cranial nerve paralysis and another had dysphagia. The radiological findings for this entity were consistent, with typical findings of hypointensity on T1- and T2-weighted magnetic resonance imaging studies and ground-glass appearance on computed tomographic scans. Four of the patients in our series had pathological confirmation. Treatment was determined by the patient's symptoms. CONCLUSION: Fibrous dysplasia should be considered in the differential diagnosis of lesions affecting the clivus. Its clinical and radiological presentations permit the establishment of the diagnosis. Its management is usually conservative, unless the patient presents with nerve compression or extensive symptomatic involvement of the condyle.     

Fibrous dysplasia of the clivus

The case of a 37-year-old man with monostotic fibrous dysplasia of the clivus is reported. This study includes clinical presentation, radiologic appearance, surgical findings, and pathology of this lesion. The significance of magnetic resonance imaging and management of this uncommon clival lesion are discussed.     

Fibrous dysplasia of the maxilla

Fibrous dysplasia is a rare disorder of the bone. It is seen in 2 main forms of presentation, monoostotic and the polyostotic form with café au lait spots and precocious puberty (McCune-Albright syndrome). Most of the cases present in the first 2 decades of life, and the lesions are rare in infants (Joseph E, Kachara R, Bhattacharya RN, et al. Fibrous dysplasia of the orbit in an infant. Pediatr Neurosurg 2000; 32: 205-208). Herein, we present a rare case of fibrous dysplasia in an infant.     

Fibrous dysplasia masqurading as plural mass

Fibrous dysplasia is a benign fibro osseous developmental anomaly. Ribs are most frequent site in mono ostotic form. Though majority of these tumours are benign, they may very rarely transform in to malignancy. The clinical features are usually presented as asymptomatic swellings in 2^nd to 3^rd decade, pain indicates rapid onset of growth or malignant transformation. Pathological fractures are reported. In X-ray chest, these rib tumors appear as plural masses creates a diagnostic dilemma. Computerised Axial Tomographics (CAT) scan usually diagnostic. Fine needle aspiration cytology is not much informative. Surgical Excision of the tumour and chest wall reconstruction is the treatment of choice of these rare benign neoplasms.