Case report 217

Five cases of fibrous dysplasia isolated to the facial bones and mandible are presented. A review of the clinical and roentgen features of facial fibrous dysplasia are described.     

Maxillofacial fibrous dysplasia: personal experience with gadoliniumenhanced magnetic resonance imaging

PURPOSE: The authors sought to identify radiological criteria assisting in the diagnosis of craniofacial fibrous dysplasia and differential diagnosis of fibro-osseous lesions by comparing computed tomography (CT) and magnetic resonance imaging (MRI) findings and histological results in 23 patients with presumed fibrous dysplasia. MATERIALS AND METHODS: From February 2000 to March 2005, 23 patients (17 women and six men, aged 9-66 years) with facial bone disease underwent CT and MRI studies. Imaging findings were compared with the results of histological examination performed within 1 month of the radiological diagnosis. RESULTS: The combination of CT and MRI led to a presumptive diagnosis of fibrous dysplasia in all cases, but histology confirmed the diagnosis in 18 cases only. In two cases that had initially been considered cyst-like variants of fibrous dysplasia and were associated with irregular enhancement at MRI, histology characterised the lesions as single locations of multiple myeloma. In one case, targeted biopsy of areas showing intense enhancement led to a diagnosis of low-grade fibrosarcoma; in the remaining two cases, the definitive diagnoses were ossifying fibroma and myeloproliferative disease. CONCLUSIONS: MRI proved useful in differentiating fibrous dysplasia from other bone diseases, defining clinical behaviour, identifying neoplastic foci within dysplastic tissue and distinguishing benign from malignant bone lesions. The authors suggest a broader use of contrast-enhanced MRI for the diagnosis and follow-up of dysplastic lesions of the facial bones and for planning appropriate surgical treatment.     

面神经管病变的多层螺旋CT评价

目的:分析面神经管病变CT表现,评价多层螺旋CT的临床价值。方法:回顾性分析面神经管病变患者35例CT资料,男24例,女11例,年龄4～51岁,平均27岁,所有患者均行多层螺旋CT扫描,常规行多平面重建和面神经管曲面重建。结果:面神经管骨折15例,其中鼓室段骨折8例,乳突段骨折5例,迷路段骨折2例;胆脂瘤型中耳炎侵犯面神经管15例;面神经瘤1例,乳突段面神经管前移2例,颞骨骨纤维异常增殖症累及面神经管2例。结论:多层螺旋CT及后处理成像能清晰显示面神经管病变,对临床诊断和治疗有重要价值。     

Computed tomography of Paget disease of the skull versus fibrous dysplasia

Objective. Radiologists are often challenged to review CT examinations of the skull without pertinent clinical information or plain radiographs. Skull lesions of fibrous dysplasia (FD) may often be confused with Paget disease (PD). The purpose of this article is to evaluate radiographic similarities and to find the signs that can differentiate PD from FD of the skull on head CT and to describe the CT imaging features of PD and FD. Design and patients. CT scans of the skull in eight cases of PD, 18 cases of FD (13 cases of skull and facial bones, five cases of only facial bones) and 10 normals were studied retrospectively. Results. Ten features were found to be similar in PD and FD and 10 other features were found to be dissimilar. The frequency of the 10 differentiating features was evaluated to determine their reliability in distinguishing one disorder from the other. The differentiating features in order of significance include: (1) “groundglass” appearance, (2) symmetry, (3) involvement of the paranasal sinuses, (4) thickness of the cranial cortices, (5) involvement of the sphenoid bone, (6) orbital involvement, (7) nasal cavity involvement, (8) presence of a soft tissue mass, (9) maxillary involvement, and (10) the presence of cyst-like changes. Conclusion. These 10 signs improve the radiologist’s skill in differentiating FD and PD.     

McCune-Albright syndrome: the patterns of scintigraphic abnormalities

This study of 22 patients with the McCune-Albright syndrome examined the scintigraphic distribution of fibrous dysplasia. The most frequently affected areas were the base of the skull (82% of patients), mandible (50%), facial bones (45%), femora (59%), and legs (64%). The least frequently affected areas included the hands (none), wrists (none), ankles (none), feet (5%), sacrum (5%), and vertebrae (9%). The distribution varied somewhat from idiopathic fibrous dysplasia but generally agreed with the distributions reported in radiographic studies of patients with the McCune-Albright Syndrome. The serum alkaline phosphatase was not an accurate predictor of the extent of fibrous dysplasia.     

Tuberous sclerosis and fibrous dysplasia

We present the case of an 11-year-old female patient with tuberous sclerosis who had a right nasal mass. CT examination revealed fibrous dysplasia involving the frontal, ethmoid, sphenoid, and vomer bones. Biopsy findings of the mass confirmed this diagnosis, and follow-up revealed marked expansion of these lesions. The authors emphasize the association of bone abnormalities and tuberous sclerosis and discuss the consideration of fibrous dysplasia as a component of this syndrome.     

Polyostotic fibrous dysplasia (McCune-Albright) with rare multiple epiphyseal lesions in association with aneurysmal bone cyst and pathologic fracture

Fibrous dysplasia, including McCune-Albright syndrome, is a genetic, non-inheritable benign bone disorder that may involve a single or multiple bone, typically occurring in the diaphysis or the metaphysis of long bones. In very rare instances polyostotic fibrous dysplasia present involvement of the epiphysis in long bones. Aneurysmal bone cysts are benign, expansile, lytic bone lesions formed by cystic cavities containing blood, that may occur de novo or secondary to other lesions of bone, including fibrous dysplasia. We report a case of an 18-year-old female with polyostotic fibrous dysplasia (McCune-Albright syndrome) with diaphyseal and unusual multiple foci of epiphyseal involvement of long bones as well as in the patella, and a simultaneous aneurysmal bone cyst of the left femoral neck with pathologic fracture. This is the first report of a simultaneous aneurysmal bone cyst in a patient with polyostotic fibrous dysplasia (McCune-Albright syndrome) with involvement of diaphysis and epiphysis of long bones, highlighting that fibrous dysplasia should be included in the differential diagnosis of polyostotic tumors involving the diaphysis as well as the epiphysis. In patients with polyostotic fibrous dysplasia there should be an active search for lesions in the epiphysis.     

骨纤维异常增殖症的影像诊断(附31例报告)

目的　探讨骨纤维异常增殖症的综合影像诊断方法及其价值。方法　报告经手术病理证实的骨纤维异常增殖症 3 1例。3 1例均摄有平片 ,其中加做CT 11例 ,MRI 6例。对比讨论X线平片和CT表现。结果　 3 1例中单骨型 18例 ,多骨型 13例 ,其中骨纤合并骨巨细胞瘤和骨纤合并脑膜瘤各 1例 ,Albright综合征 1例。X线分型 :囊肿型 (18灶 ) ,弥漫型 (3 0灶 ) ,丝瓜络型 (2灶 ) ,虫噬型 (2灶 )。CT表现主要分为囊状膨胀型改变 (3 8灶 )和硬化型改变 (7灶 )。结论　骨纤的影像诊断目前仍以X线平片为主 ,颅面部的病变则CT占优 ,两者结合对大部分骨纤可做出正确的诊断     

Helical CT and diagnostic evaluation of cranio-facial fibrous dysplasia]

PURPOSE: To evaluate the role of helical CT in the evaluation of skull abnormalities seen in fibrous dysplasia. MATERIALS AND METHODS: Prospective study on 6 cases with cranio-facial fibrous dysplasia (3 males and 3 females) aged 8 to 59 years old, evaluated with plain radiographs, helical CT and, in 1 case, MRI. Helical CT was performed in 3 cases on a CT Twin scan (Elscint), in 3 cases on a Somatom Plus scan (Siemens). Multiplanar reconstructions and 3D reconstructions were done in all cases. 4 cases had a histopathological confirmation of fibrous dysplasia lesions by bone-biopsy (3 cases) or surgical biopsy (1 case). RESULTS: The 6 cases included sclerotic form in 3 cases, cystic variety in 1 case, polyostotic variety in 1 case, mixed form in 1 case. Topographic localizations of fibrous dysplasia were skull base involvement in 1 case, multizonal skull involvement in 4 cases, maxillo-mandibulary involvement (cherubism) in 1 case. CONCLUSION: Helical CT is an optimal method to evaluate the skull lesions of fibrous dysplasia. The review of source images must always be done. 3-dimensional bone reconstructions are better to visualize the anterior cranial vault and skull base dysmorphy. Helical acquisition is a compromise in case by case between the dose of irradiation and the quality of source images.     

CT and MRI of congenital sinonasal ossifying fibroma

We report a 9-year-old boy with a sinonasal ossifying fibroma, probably congenital, with atypical findings on CT and MRI. CT revealed a soft-tissue density mass in the sphenoethmoidal sinuses, nasal cavity and right maxillary sinus with a few foci of calcification and with remodelling and destruction of the adjacent facial bones. MRI showed high signal on T2- and intermediate signal on T1-weighted images. A thin, partly enhancing outer shell and some nonenhancing septa were visible on contrast-enhanced images. MRI also showed the tumour to extend into the anterior cranial fossa. Subtotal removal was performed. We compare our findings with reports in the literature and discuss the differences from fibrous dysplasia. Received: 30 September 1998 Accepted: 18 December 1998     

颅面骨纤维异常增殖症的二维CT和三维CT诊断

笔者报告了２６例颅面骨纤维异常增殖症的ＣＴ所见，其中６例进行了三维ＣＴ重建，结果显示二维ＣＴ能更精确地反映病变的密度差异和解剖细节，对估价颅面的孔、裂、管、道、腔、窦等受累情况尤佳，对建立骨纤维异常增殖症的诊断和确定病变范围很有价值。三维ＣＴ主要适用于骨性狮面的病例，它能生动地表现颅面不对称畸形，对术前治疗计划的制定很有帮助，是对二维ＣＴ的重要补充     

Hyperostotic Esthesioneuroblastoma: Rare Variant and Fibrous Dysplasia Mimicker

A 65-year-old male presented with a 3-year history of orbital symptoms. An imaging-based diagnosis of fibrous dysplasia involving the skull base was made at another institution. CT showed a diffuse sinonasal mass and ground-glass appearance of the bones of the anterior skull base with bony defects and mucocele formation. MRI demonstrated an accompanying intracranial and orbital rind of soft tissue mass along the hyperostotic bones. FDG-PET showed corresponding intense hypermetabolism. Small cysts were observed at the tumor-brain interface. Biopsy revealed esthesioneuroblastoma with bone infiltration that is compatible with the hyperostotic variant of esthesioneuroblastoma. There are a few cases of hyperostotic esthesioneuroblastoma reported in the literature.     

颅面骨纤维异常增殖症的影像病理学表现

目的 探讨颅面骨纤维异常增殖症的影像表现和病理特点.方法 回顾性分析42例经手术病理证实的颅面骨纤维异常增殖症,对其影像学表现和病理特点进行对比分析.结果 42例中单发型35例,多骨型7例.磨砂玻璃状改变是骨纤维异常增殖症特征性CT表现,占CT检查患者的79.3%,纤维异常增殖症的病理成分纤维和纤维样组织,在磁共振的T_1WI和T_2WI上均表现为低信号;如病灶发生出血、坏死或囊变,T_2WI信号也随之发生改变.结论 CT和MRI扫描对颅面骨纤维异常增殖症的诊断具有重要意义.     

长骨纤维结构不良的CT及MRI诊断分析

目的探讨CT及MRI对长骨纤维结构不良的诊断及鉴别诊断价值。方法回顾性分析经病理证实的21例长骨纤维结构不良患者。所有患者均行CT平扫,MRI平扫及增强扫描19例。结果单骨型20例,其中股骨11例,胫骨4例,肱骨3例,尺骨及腓骨各1例;多骨型1例,同时累及同侧股骨及胫骨。CT表现呈磨玻璃样改变11例,囊状膨胀透亮改变8例,丝瓜络样改变2例。对照CT,呈磨玻璃样改变时MRI上T1WI呈等、稍低信号,T2WI呈不均匀等、稍高信号;呈囊状膨胀透亮改变时,T1WI呈低信号,T2WI呈明亮高信号;呈丝瓜络样改变时,T1WI呈不均匀稍低信号,T2WI呈不均匀稍高信号;增强后呈不同程度边缘或片状不均匀强化。结论 CT可显示长骨纤维结构不良的病变范围及细节等,MRI有助于反映病变组织成分,CT结合MRI在纤维结构不良的诊断及鉴别诊断中有重要价值。     

骨纤维异常增殖症的影像诊断

目的:探讨骨纤维异常增殖症的影像诊断方法及其价值。方法:搜集经手术病理证实的骨纤维异常增殖症34例,所有病例均行X线检查,其中加行CT 10例,MRI 2例,加行Gd-DTPA增强扫描1例。结果:单骨型27例,其中单骨单灶26例,单骨双灶1例;多骨型7例,其中单肢型2例,1例累及单侧5根肋骨和3节胸椎。X线平片和CT上表现为囊状改变22例,磨玻璃样改变8例,丝瓜络样改变3例,虫蚀样改变1例,合并病理骨折3例。结论:大多数骨纤维异常增殖症具有典型影像学表现,其检查方法仍以X线平片为主,观察复杂部位及病灶内改变以CT为优。低髓腔硬化征对诊断该病具有一定意义。     

骨血管源性肿瘤的影像学诊断(附23例报告)

目的探讨骨血管源性肿瘤的影像学特点,旨在提高其诊断水平。方法对发生在不同部位的23例骨血管源性肿瘤的X线片、CT片和MRI片进行回顾性分析。结果19例骨血管瘤典型影像学表现根据其发生部位分为3种:椎体为栅栏状或网眼状;颅骨为放射状;长管状骨为多囊状或泡沫状。19例中术前误诊为骨纤维异常增殖症和骨巨细胞瘤各1例。4例骨血管肉瘤的影像学主要表现为溶骨性骨质破坏或骨质破坏与成骨增生混合存在。术前误诊为骨纤维异常增殖症及脊索瘤各1例和未定性2例。4例术后虽然进行放、化疗,但仍有2例在短期内发生肺及纵隔转移。结论典型骨血管瘤的影像学具有一定的特征性表现,结合临床资料,一般可做出诊断。而骨血管肉瘤的影像学表现无特征性。     

颌面部骨纤维结构不良的X线诊断和鉴别诊断

A radiologic-pathologic correlative study was carried out on 43 cases with fibrous dysplasia of the facial bones with emphasis on basis for radiological diagnosis. The x-ray manifestations according to density changes are classified into three types: sclerotic, osteolytic and mixed. The lesion extends along the longitudinal axis in the mandible whereas in the maxilla, the lesion spreads in a diffuse pattern along the wall of the maxillary antrum with preservation of maxillary contour. The authors considered that fibrodysplasia and ossifying fibroma are different disease entities and should be distinguished by combination of clinical, radiologic and pathologic evidences.     

Scintigraphic evaluation of polyostotic fibrous dysplasia

Bone scintigraphy is a sensitive imaging modality for detecting early lesions and polyostotic involvement in fibrous dysplasia. Common findings include multiple areas of focal uptake that are often unilateral and typically involve the ribs, tibia, femur, and craniofacial bones. A knowledge of various skeletal manifestations of fibrous dysplasia is helpful to distinguish it from Paget's disease, osteoblastic metastasis, and fractures. Several recent cases representing varying involvement of fibrous dysplasia are presented and the literature is reviewed.     

Ossifying fibroma of the long bones. Radiological diagnosis, differential diagnosis and management implications

We report a case of ossifying fibroma of the long bones (OFLB). This lesion, occurring mainly during the first decade of life, typically affects the tibial diaphysis and clinically presents as a painless bony enlargement. Radiographic features include an osteolytic cortical expansion, containing diffuse calcifications, and separated from the medullary by a thick cortical rim. CT appears to be the examination of choice to define these signs and permits differentiation from monostotic fibrous dysplasia and from adamantinoma (by demonstrating the presence or absence of diffuse high attenuation values). The importance of making the differential diagnosis is stressed, as prognosis and management of OFLB, fibrous dysplasia and adamantinoma may vary considerably.     

Unexpected finding of elevated glucose uptake in fibrous dysplasia mimicking malignancy: contradicting metabolism and morphology in combined PET/CT

Fibrous dysplasia is a common benign disorder of bone in which fibro-osseous tissue replaces bone spongiosa. Lesions have a typical appearance on computed tomography (CT) images and regularly show a markedly increased uptake in bone scintigraphy using ^99mTc-labelled methylene diphosphonate (^99mTc-MDP) as radiotracer. The glucose avidity of these lesions depicted by positron emission tomography (PET) using the radiolabelled glucose derivative ¹⁸F-fluoro-2-deoxy-glucose (FDG) is less well known since FDG-PET does not have a role in the assessment of this disease. However, single cases have been reported in which fibrous dysplasia was present in patients undergoing FDG-PET scanning for oncological reasons, and no significant FDG uptake was observed for lesions identified as fibrous dysplasia. We report on a 24-year-old man with known fibrous dysplasia who underwent combined FDG-PET/CT scanning because of suspected recurrence of testicular cancer. In contrast to prior reports, a markedly elevated uptake of FDG was seen in numerous locations that were identified as fibrous dysplasia by CT. Based on this result, we conclude that fibrous dysplasia may mimick malignancy in FDG-PET and that coregistered CT may help to resolve these equivocal findings.