Atta ur Rehman*, Nida Murad**, Umar Khitab***
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J Pak Dent Assoc.2011; 20 (2): 121-124
Fibrous dysplasia is a non-neoplastic developmental disorder of bone. This report discusses a case of swelling of right maxilla for past five years..
A 47-year-old female presented to the Oral and Maxillofacial department, Khyber College of Dentistry Peshawar with mild pain and swelling on right the side of maxilla since 5 years. Presentation was preceded by a history of multiple extractions in the past. Examination extra orally had no significant facial asymmetry. Intra orally there was significant bony hard swelling and bicortical bony expansion with dimensions of 3x5cm. Plain radiograph showed a radioopaque bony mass involving right maxillary alveolus and maxillary tuberosity. The incisional biopsy of bony mass diagnosed histologically as fibrous dysplasia. Fibrous dysplasia should be considered in the differential diagnosis of slowly progressing bony mass with associated pain in old age adults.
Fibrous dysplasia, Maxillary bone fibrous dysplasia, Occurrence.
Fibrous dysplasia is a benign slowly growing primary disorder of bone in which the normal cancellous bone is replaced by immature woven bone and fibrous tissue 1. This condition was first recognized by von Recklinghausen in 18912.Since then, a large number of cases have been reported and considerable advances have been made in the understanding and treatment of the disease. 3It has no sex preference and usually manifests before the 3rd decade of life and often found during childhood mainly in Caucasians and asians.4, the relation of growth stimulus and mutation of GNAS 1 found in osteobalstic cells describes the pathophysiology of fibrous dysplasia in growing children. Osteoblastic cells expressing this mutation have a higher DNA synthesis than normal bone cells. The growth of these cells is faster, leading to an inappropriate differentiation of mesenchymal cells. Involved bone cells are immature. 6, 7Fibrous dysplasia has two basic clinical forms, namely the monostotic and the polyostotic forms.3The monostotic form constitutes about 70% of cases and has predilection for the ribs and femur. 7,8 Monostotic form involve craniofacial skeleton in 10% of cases.8,9It manifests as slowly enlarging, painless bony mass and may involve virtually any bone in the body. Deformity is progressive and by mass effect there may be impingement on other structures and functional impairment. 10, 11 Malignant degeneration occurs in less than 1% fibrous dysplasia, mostly osteosarcoma. For unknown reasons, monostotic and craniofacial lesions have the greatest potential for malignant degeneration and radiation therapy has been found to increase the risk by 400-fold. Pain, rapid growth of lesion and a dramatic elevation of serum alkaline phosphatase may herald malignant transformation.13,14,15 Histological examination provides the basis for an accurate diagnosis and is characterized by multiple small and irregular spicules of immature bone superimposed on a background of moderately cellular fibrous connective tissue 9
However, ancillary investigations, like computerized tomography (CT) scan shows the characteristic ‘ground glass’ appearance in the sclerotic form and non-homogenous appearance in the cystic and mixed form, may be needed to complement findings of histopathology.The interest of the present case is, the diagnosis of fibrous dysplasia in fifth decade of life, an unusual occurrence.
A 47-year-old female was referred to the department of Oral and Maxillofacial Surgery KCD. She complained of swelling on the right side of the maxilla. A detailed history was taken. The swelling was present since 5 years and gradually increased in size for the last 2 years. She had history of multiple extractions. Severe pain and pus discharge started 6 months back and was treated with antibiotics and pain killers at local hospital. She was referred to Oral and Maxillofacial department for proper evaluation and management. She also complained of joint pain and hypertension for which she was taking medication. Patient was married with five children and had no known hypersensitivities.
The extra oral examination revealed no significant findings. Intra orally there was swelling in the posterior region of the right side maxilla, 3x5cm involving alveolus and maxillary tuberosity with bicortical expansion (Fig 1). On palpation the swelling was bony hard, non-compressible, and associated teeth were non mobile. No pus was noticed. Radiographs of facial bones had shown hazzy appearance in the right maxillary posterior alveolus and tuberosity (Fig 2). An incisional biopsy was planned and base line investigations were carried out. Patient hemoglobin level was found low (8.2g/dl). In differential diagnosis ossifying fibroma and osteosarcoma were considered. The histopathology request was sent to shaukat khanum memorial hospital histopathology laboratory. The report confirmed fibrous dysplasia. Surgical excision of maxillary bone fibrous dysplasia was carried out in toto
Fibrous dysplasia results from a defect in osteoblastic differentiation affecting the final maturation of the bone, described as a non-familial, developmental disorder of the bone. 2It usually manifests before the 3rd decade of life. The monostotic form is more common and affects the 20 to 30 years age group while polyostotic Fibrous Dyaplasia has its onset mainly in children younger than 10 years of age9, 10, 16This patient fell beyond the age group described in the literature which is unusual occurrence, diagnosed with monostotic form of fibrous dysplasia. Monostotic fibrous dysplsia is predominantly found in maxilla8, 13 as was in this case involving alveolus and tuberosity. The history of multiple extractions preceding the onset of the pathology in this case may be of interest as trauma can be the provoking factor in the initiation of this pathology. Few reports in literature has described a cause-and-effect consistent with fibrous dysplasia. association between fibrousdy splasiaan d trauma.1 1 , 1 2 Trauma during puberty when bone development is at its maximum may have implications on the development of tumours of the bone, but this may be difficult to establish in the present case as bony growth have concluded prior to the age when patient sustained the trauma from extractions. Any cranial or facial bone can be affected by fibrous Dysplasia and the clinical features associated will depend upon the bone or bones affected.15, 16 Signs and symptoms of fibrous Dysplasia include bone pain, pathological fractures and bone deformities. This case presented with complaint of mild to moderate degree of pain often referring to temple region and was also unable to perform oral function comfortably. Serum alkaline phosphatase (ALP) is occasionally elevated, but calcium, parathyroid hormone level, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D levels in cases of fibrous Dysplasia are normal. 12This case was presenting with normal base line investigation except with low Hb=8.2g/dl
Establishing the diagnosis of fibrous dysplasia requires close cooperation between clinician, radiologist and pathologist which was demonstrated very well in the case reported. It may at time present a diagnostic challenge.
14 This case report was confirmed histologically as fibrous dysplasia of right maxilla through incisional biopsy. This is occasioned at times by the nonspecific histological and radiological appearance which may result in poor characterization of the lesion.15The radiological features of fibrous dysplasia are diverse and are dependent upon the proportion of mineralized bone to fibrous tissue in the lesion.17 Early fibrous dysplasia of craniofacial bones is radiolucent with either ill defined or well defined borders, and may be unilocular or multilocular. As the lesions mature , the bonyd efects acquireamixed radiolucent/radiopaque appearance, and established fibrous dysplasia exhibits mottled radiopaque patterns often described as resembling ground glass, orange peel or fingerprints, with ill defined borders blending into the normal adjacent bone. This case was presenting the mature form of fibrous dysplasia with mottled radiopacity pattern and had displaced the floor of adjacent maxillary sinus upward. Histologically, fibrous dysplasia comprises irregular trabeculae of woven bone, blending into the surrounding normal bone and lying within a cellular fibrous stroma with osteoblast progenitor cells resembling fibroblasts. 18 These trabeculae of woven bone have been said to resemble Chinese script writing.1This case report also reveals presence of immature woven bone arranged in irregular pattern surrounding fibroblastic proliferation Therapeutic indication depends on the course of tumour and the development of complications. This could range from mere observation with serial radiological follow-up, medical therapy with systemic corticosteroid to surgical intervention. The surgical option was advocated by excision of tumor. 12, 18