Fibrous dysplasia and ossifying fibroma of the paranasal sinuses

Paediatric paranasal sinus fibrous dysplasia

Fibrous dysplasia in the bony walls of a paranasal sinus is a developmental tumour that is associated with a marked facial deformity. Delay in hospital presentation contributes to the destructive resection techniques employed and the management outcome. Our study looks at the factors for delay in hospital presentation and the management outcome by a retrospective review between January 1997 and December 2018. Of 43 children (M: F 1:1.2) with a mean age of 12 ± 1.75 years, the maxillary bones were mostly affected. All underwent surgical resection with good management outcomes except for maxillectomy. Tumour recurrence was noted in five and there was no mitotic cell at histology. The clinical symptoms of fibrous dysplasia vary in severity and age of onset, often with late hospital presentation already with complications. Health education is needed to reverse this trend.

Endoscopic Transnasal Management of Giant Paediatric Sinonasal Ossifying Fibroma

The ossifying fibroma is a rare fibro-osseous benign lesion of bone in the head and neck region. The mandible is the most common site reported followed by maxilla and other bones of the skull. A paediatric male presented with protrusion of the right eyeball for one-month duration. Further evaluation by diagnostic nasal endoscopy revealed a smooth mass confined to the superior and middle meatus on the right side. Computed tomography of paranasal sinus showed a large heterogenous bony lesion involving the ethmoid and sphenoid sinus and extending laterally into the orbit and superiorly into anterior skull base. Endoscopic biopsy was suggestive of ossifying fibroma. Transnasal endoscopic excision of the lesion was done and the patient is currently on follow-up. This case is reported for the rarity of presentation and the difficulties in management.

Anatomical and volumetric analysis of fibro-osseous lesions of the craniofacial skeleton

PURPOSE

Our study aimed to provide volumetric data relating to fibro-osseous lesions of the craniofacial skeleton, in order to highlight risk factors due to the different entities, and to guide clinical decisions for jeopardized patients.

METHODS

Volumetric measurements of osteomas and ossifying fibromas were performed by applying the open-source software ITK-Snap to cone-beam computed tomography images. DICOM datasets were imported, identified, and delineated using semiautomatic segmentation; this was then verified using manual segmentation. The volumes of the lesions were computed automatically in cubic millimeters using the program. For statistical investigations, descriptive statistics and independent Student t-tests were performed. Additionally, Pearson's correlation was applied as a bivariate analysis. Values of p < 0.05 were considered significant.

RESULTS

45 patients (11 male and 34 female) were included in this study. The mean volumes were 10.02 ± 18.79 cm³ for osteomas and 4.80 ± 5.71 cm³ for ossifying fibromas (p = 0.016). Males (12.81 ± 20.38 cm³) presented significantly larger volumes than females (5.43 ± 10.32 cm³) (p = 0.042). With regard to shape, morphology, and affection of surrounding anatomical structures, irregular shape (p = 0.001; p = 0.037), multilocular morphology (p = 0.001; p = 0.037), nerve affection (p = 0.001; p = 0.002), tooth affection (p = 0.001; p = 0.594), cortical bone exceedance (p = 0.033; p = 0.001), and clinically visible symptoms (p = 0.004; p = 0.001) were statistically significantly associated with a larger volume of both entities.

CONCLUSION

Volumetric analysis revealed that osteomas significantly exceeded the mean size of ossifying fibromas, supporting the argument that special attention should be paid to this entity. In cases of difficult histopathological examination, lesions with irregular shape, multilocular morphology, nerve and tooth affection, cortical bone exceedance, and clinically visible symptoms should be considered for close clinico-radiological follow-up, irrespective of the entity.

Central ossifying fibroma of mandible

Ossifying fibroma (OF) is a rare, benign, fibro-osseous lesion of the jawbone characterised by replacement of the normal bone with fibrous tissue. The fibrous tissue shows varying amount of calcified structures resembling bone and/or cementum. The central variant of OF is rare, and shows predilection for mandible among the jawbone. Although it is classified as fibro-osseous lesion, it clinically behaves as a benign tumour and can grow to large size, causing bony swelling and facial asymmetry. This paper reports a case of large central OF of mandible in a 40-year-old male patient. The lesion was treated by segmental resection of mandible. Reconstruction of the surgical defect was done using avascular fibula bone graft. Role of three-dimensional printing of jaw and its benefits in surgical planning and reconstruction are also highlighted.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Orbit ossifying fibroma - Case report and literature review

Background:

Ossifying fibroma (OF) is benign bone lesions, most frequent in young children, more common in the maxillary sinus and mandible (75–89%), the pathogenesis of the tumor is not clear, there are many subtypes of OF. This paper aims to report an OF a case and literature review.

Case Description:

Male, 19 years old, with a progressive history proptosis since 2012, diagnosed as a right supraorbital lesion at an external service and assigned to conservative management. Then, he evolved with double vision, which worsened in February of 2018, associated with a moderate headache. On admission: proptosis and downward deviation of the right orbit was noticed on the physical exam and with exception of limited right upgaze, external ocular movements were maintained. Head computed tomography showed a multiloculate expansive osteolytic lesion at the right orbital roof. On magnetic resonance imaging, the lesion had an inner content with septations, T1-weighted imaging heterogeneous signal, T2-weighted imaging high signal intensity, and peripheral contrast enhancement. The patient underwent a right frontal craniotomy with a gross total resection and the postoperative follow-up was uneventful. Menzel reported the first case in 1782. The clinical findings depend on localization. There are five subtypes. In general, the lesions have a radiological appearance with hyperdense boundary and cause deformity and destruction in bones with high recurrence risk. Radical resection is curative.

Conclusion:

As a result, the correlation of clinical, radiologic, and pathologic data is significant while going for a specific diagnosis in cases of craniofacial fibrous lesions. Total excision is the best treatment, but it can recur.

Unilateral visual loss resulting from orbital encroachment of an ethmoidal juvenile trabecular ossifying fibroma

Ossifying fibromas are mainly found in the mandible and maxilla. Reports of them arising in the ethmoid sinuses and orbits are rare. We present a case of an otherwise healthy 20-year-old man with gradual onset of right visual disturbance signified by right relative afferent pupillary defect due to a large unilateral ossifying fibroma arising from the ethmoid sinus compressing the medial half of the right orbit. We emphasise the multidisciplinary combined endoscopic endonasal and external approach to ensure a successful debulking of the fibroma.

Juvenile Trabecular Ossifying Fibroma-a Case Report

Ossifying fibroma is a benign osteogenic mesenchymal tumor that is classified in the fibro-osseous lesions. Fibro-osseous lesions contain minerals, blood vessels, and giant cells that have the same radiographic and pathologic features but have different clinical behaviors, and were replaced with the normal bone. These lesions include fibrous dysplasia, cemento-osseous dysplasia, and ossifying fibroma. Juvenile ossifying fibroma is a type of uncommon and has invasive behavior, high incidence and occurs in young men, especially in maxilla, and is different from the type of adult in age, location, and clinical behavior and microscopic view. Pathologically, ossifying fibroma is divided into two types of trabecular and psammomatoid. The trabecular type is characterized by the presence of the osteoid trabeculae and the woven bone, and the type of psammomatoid by the presence of round, integrated, and small ossicles that are similar to the components of the psammoma. The purpose of this report is the clinical examination, radiography, pathology, and the treatment of a rare case of ossifying fibroma (trabecular) in mandible in a 7-year-old boy.

Ossifying fibromas of the paranasal sinuses: diagnosis and management

Fibro-osseous benign lesions rarely affect the sinonasal tract and are divided into 3 different entities, namely osteoma, fibrous dysplasia and ossifying fibroma. They share several clinical, radiological and histological similarities, but have different behaviours. Ossifying fibroma, and in particular the "juvenile" histological subtype, may have a locally aggressive evolution and a high risk for recurrence if removal is incomplete. The purpose of the present study is to compare the clinical behaviour of ossifying fibroma with the other benign fibro-osseous lesions; highlight different behaviour between the histological subtypes; compare the advantages, limitations and outcomes of an endoscopic endonasal approach with reports in the literature. We retrospectively reviewed 11 patients treated for sinonasal ossifying fibroma at a tertiary care centre. All patients underwent CT scan, and MRI was performed in cases of cranial base involvement or recurrence. Pre-operative biopsy was performed in cases where it was possible to use an endoscopic approach. One patient underwent pre-operative embolisation with ipsilateral visual loss after the procedure. Depending on its location, removal of the tumour was performed using an endoscopic (n = 7), or an external (n = 3) or combined (n = 1) approach. Histopathologically, 5 patients presented the conventional type, 5 the juvenile psammomatoid variant, which was associated in 1 case with an aneurismal bone cyst, and 1 case presented the trabecular juvenile variant. Three patients affected by the juvenile psammomatoid histological variant presented invasion of the skull base and underwent a subtotal removal that subsequently required, due to the regrowth of the remnant, a transbasal approach. Clinical, radiological and histological findings should all be considered to establish differential diagnosis among fibrous osseous lesions. More studies are necessary to conclude if the localisation and extension of the disease at the time of diagnosis is more important than the histological variant. An endoscopic approach is the first choice in most of cases even if an external open approach may be necessary in selected patients.

A clinicoradiologic analysis of symptomatic craniofacial fibro-osseous lesions

Objective

To outline the clinical and radiologic aspects of symptomatic craniofacial fibro-osseous lesions and to study the appropriate surgical management with follow-up results.

Study Design and Setting

A retrospective review of 11 patients who underwent surgical treatment during 1985 to 2004 in a tertiary health care center.

Results

Most (72.7%) cases were of fibrous dysplasia and were under 25 years of age (72%). Maxilla was the most common bone involved (81%). Lateral rhinotomy was the main approach for surgical resection. One patient underwent bilateral optic nerve decompression (left side therapeutic and on right side prophylactic). Six (54.5%) cases had recurrences that were managed by either radical surgery (total maxillectomy) or by further shaving off the lesion.

Conclusion

Treatment of craniofacial fibro-osseous lesions is highly individualized. A conservative approach may not be able to treat all cases of craniofacial fibro-osseous lesions. A more radical approach that includes a craniofacial resection or a total maxillectomy may be warranted in few cases.

Juvenile ossifying fibroma of mandible: a case report

Fibro osseous lesions are benign mesenchymal skeletal tumours in which mineralized tissue, blood vessels and giant cells, in varied proportions replace normal bone. Included in this group are fibrous dysplasia (FD), cherubism, ossifying fibroma and osteoblastoma. Although fibro osseous lesions have similar histologic and radiographic features, they may exhibit a wide range of biological behaviours. Because the histologic appearance does not predict the rate of growth or prognosis, treatment is based on the clinical and biologic behaviour of the tumour. The term "Juvenile active ossifying fibroma"(JAOF) has been given to a less common, more aggressive variant of the central ossifying fibroma which occurs primarily in children and young adults. This lesion has been described in literature under variety of terms like "aggressive psammomatoid ossifying fibroma" or "juvenile ossifying fibroma". We are presenting a case of Juvenile aggressive ossifying fibroma in a 17 years old girl who reported to our institute.

Retrospective Analysis of Ossifying Fibroma of Jaw Bones Over a Period of 10 Years with Literature Review

OBJECTIVE

The purpose of this retrospective analysis is to document and discuss the features, treatment rendered and result of 25 histologically proven cases of ossifying fibromas of jaw bones operated by a single surgeon over a period of 10 years.

MATERIALS AND METHODS

The records of ossifying fibroma were obtained from the archives of Oral and Maxillofacial Surgery at Maulana Azad Institute of Dental Sciences (MAIDS) from 2001 to 2011. Only those cases were included in the study where definitive surgery was performed based on clinical, radiological & histopathological features.

RESULTS

Twenty-five patients were analyzed with a final diagnosis of ossifying fibroma comprising of 14 males (56 %) and 11 females (44 %). The age range was 11-45 years with a mean of 24.12 years. Mandible was involved in 72 % and maxilla in 28 % cases with a predominance of mandibular posterior [19 (76 %)] cases. The study showed similar findings in regard to clinical, radiographic & histological features of ossifying fibroma as compared to other studies. It also showed that the treatment rendered in the form of eneucleation, curettage or resection of the lesion depending on its stage and extent were adequate, as no recurrence has been reported till date.

CONCLUSION

Enucleation is preferred in small and well demarcated lesions. Curettage should be done in relatively large lesions with ill defined borders, not involving basal bone of mandible or cortical perforation. Resection should be reserved for aggressive and extensive cases with involvement of basal bone or perforation of cortices.

Ossifying fibroma of the nose and paranasal sinuses

BACKGROUND

The purpose of this work was to perform a systematic review regarding ossifying fibroma and its multiple variants of the paranasal sinuses, and to identify any clinical differences between the multiple variants.

METHODS

A search of the U.S. National Library of Medicine (PubMed) database was performed for the non–Medical Subject Heading (MeSH) search term “ossifying fibroma.” The bibliographies of the retrieved manuscripts were searched to identify additional potentially relevant articles. Finally, textbooks of head and neck pathology were searched to identify peer-reviewed literature that addresses the histopathology of ossifying fibroma and its variants. Abstracts were screened by 2 of the authors to identify reports of ossifying fibroma lesions (and its variants) that involved the paranasal sinuses. Extracted data from case reports or case series included the clinical presentation, age, gender, site of involvement, surgical approach, treatment outcome, follow-up period, and recurrence rate. Information derived from cases is summarized in tables, and simple descriptive statistics were applied to the data.

RESULTS

A total of 137 distinct patients were identified in 103 reports. Extracted data did not show any appreciable difference in clinical presentation or outcomes. Data on recurrence of these lesions was often limited by a lack of follow-up.

CONCLUSION

Although differentiation between the subtypes of ossifying fibroma can be made histologically, and a diverse nomenclature exists, there does not appear to be any overriding clinical significance to the histopathologic differentiation of OF variants.

Tooth in the nose: unusual presentation of a misdiagnosed maxillary ossifying fibroma

Fibro-osseous lesions involving the paranasal sinuses are uncommon, and making a determination of their histologic type is challenging. Correlating clinical and surgical findings with radiologic and histologic characteristics is essential for making a definitive diagnosis. We describe a case of misdiagnosed maxillary ossifying fibroma presenting as a solitary mass that completely filled and enlarged the left maxillary sinus. Another interesting finding was the presence of a molar tooth embedded in the tumor. We briefly comment on the genesis, natural course, and differential diagnosis of this lesion.

Frontal sinus osteoma with osteoblastoma-like histology and associated intracranial pneumatocele

Osteomas of the cranial sinuses are rare, benign bony tumors that can be complicated by the formation of an intracranial pneumatocele. If not treated promptly, a pneumatocele can lead to abscess formation, meningitis, or ventriculitis. In the present case, an intracerebral pneumatocele was formed when an 18 cm(3) osteoma breached the posterior wall of the frontal sinus creating a one-way valve through which air could enter the intracranial cavity. The patient presented after forceful sneezing with nonspecific symptoms of headache, nausea, and vomiting. CT demonstrated a frontal collection of loculated air with mass effect within the left cerebral hemisphere. A partly mineralized mass occupied the left superior nasal ethmoid sinus and left frontal sinus. Of interest pathologically in this case, the tumor had a substantial osteoblastoma-like component. Surgical repair involved frontal craniotomy to remove the osteoma and debride frontal sinus mucosa, plugging the frontal nasal ducts and sinus with fat and bone wax, and dural restoration using an underwater closed drainage system to vent intracranial air and stabilize the patient.

Paranasal sinus and skull base fibro-osseous lesions: when is biopsy indicated for diagnosis?

BACKGROUND

Paranasal sinus fibro-osseous (FO) lesions represent a heterogeneous group, often sharing overlapping radiographic and pathologic features posing a dilemma in accurate diagnosis. The objective of this study was to correlate preoperative radiologic and postoperative histologic diagnosis to help guide a diagnostic algorithm.

METHODS

Retrospective analysis of 60 FO lesions between 1994 and 2010.

RESULTS

The mean age was 42.3 years with average follow-up of 12.5 months. The preliminary radiologic diagnosis was osteoma in 22 (36.7%), fibrous dysplasia (FD) in 9 (15%), ossifying fibroma (OF) vs FD in 5 (8.3%), and OF in 3 (5%) cases. The diagnosis was indeterminate in 21 (35%) cases. Management consisted of excision in 29 (48.3%), observation in 17 (28.3%), and biopsy in 14 (23.3%) patients. For patients undergoing resection or biopsy, positive predictive value of preoperative radiology was 100% (10/10) for osteoma, 85.7% (6/7) for FD, and 33.3% (1/3) for OF cases. For the indeterminate lesions, most common pathologic diagnoses for 21 patients included osteoma in 4 (17.4%), arrested pneumatization in 3 (14.3%), OF in 3 (14.3%), and FD in 2 (9.5%). For FD vs OF cases, 3 underwent surgery, revealing osteoma, FD, and OF in 1 patient each.

CONCLUSION

In this series, radiologic-histopathologic correlation was high for osteoma and FD and low for OF and OF vs FD. This data suggests that patients with classic radiologic characteristics of osteoma and FD may be observed, unless resection is warranted based on clinical symptomatology. Preoperative diagnosis of OF, OF vs FD, or indeterminate lesions may warrant a biopsy to establish firm diagnosis to guide definitive management, especially if preoperative computed tomography (CT) imaging is concerning for an aggressive FO neoplasm.

Ultrastructual morphology of juvenile psammomatoid ossifying fibroma

We investigated the ultrastructural morphology of the hard tissue in a fibro-osseous lesion. Bone samples were obtained from a juvenile psammomatoid ossifying fibroma and were observed under a scanning electron microscope. The lesion had a spongy lamellar structure containing bony tissue. On histological examination, resorbing preexisting lamellar bone associated with a large number of cathepsin K-positive osteoclasts was confirmed. Scanning electron microscopy revealed the bony material to have a cribriform structure and to indicate resorption related to osteoclasts throughout the tumor. These characteristic findings revealed the presence of active bony reconstruction and destruction in this lesion. The spongy calcified structure observed by scanning electron microscopy expressed the characteristic ground glass appearance in computed tomography of this patient. This remarkable activation of osteoclasts may deeply relate to characteristic calcified structure in this lesion. Observation of hard tissue structure under a scanning electron microscope may shed light on the pathology of fibro-osseous lesions in the head and neck.

Ossifying fibroma of the jaws: report of two cases and literature review

Ossifying fibromas are uncommon benign tumors of the craniofacial skeleton thought to originate from the periodontal ligament. Most are small and incidentally diagnosed with routine dental radiographs. With larger lesions, patients may complain of an abnormal bite or an enlarging mass. This tumor involves slow-evolving growth with deforming swelling generally arising in the mandible, with possible early tooth displacement. From the radiological perspective, more than 50% of the lesions exhibit an expansion of the jaws and 53% shows well-defined unilocular radiolucencies and 40% are mixed radiolucent-radiopaque lesions. The lesions exceptionally can be radiopaque. Ossifying fibroma presents several variant histopathological subtypes. The overlapping clinical and histopathological features of these subtypes have led to diagnostic dilemma and confusion. Complete excision of this tumor has become a necessity since it is notorious for recurrence. We present here two cases of ossifying fibroma of the jaws along with insight into the literature review.

Fibrous dysplasia-like appearance of the frontal process of the maxilla on CT: prevalence in North China

The frontal process of the maxilla occasionally shows a localized FD-like appearance. The purpose of this study was to determine its prevalence and findings on CT. A retrospective study of 1000 consecutive paranasal sinus CT scans was preformed on outpatients without a history of trauma or previous surgery in our hospital during 6 months. CT images were interpreted independently by 2 experienced head and neck radiologists on a PACS system in a bone window setting. Of the 1000 patients (546 males; 454 females), 51 (5.1%,41 males and 10 females) had an FD-like appearance in the frontal process of the maxilla. There was a statistically significant difference between sexes (P < .001). Twenty-nine (56.9%) entities arose from the right frontal process and 22 (43.1%) from the left frontal process. These entities, with well-defined margins, were located at the base of the frontal process of the maxilla, appearing as an ovoid or triangular configuration on axial-plane CT and as a spindle or elliptic shape on the coronal plane. The mean maximal diameter was 9.8 mm (range, 3.6-16.1 mm). These entities exhibited a pagetoid appearance (type I) in 37 (72.5%), a ground-glass appearance (type II) in 8 (15.7%), and a cyst-like appearance (type III) in 6 (11.8%) patients on CT. The FD-like appearance of the frontal process of the maxilla is not rare and can be readily detected by CT.

Ossifying fibroma of the maxillary sinus at the Kara (Togo) Teaching Hospital

INTRODUCTION

Ossifying fibroma of the jaw is a benign tumorous disease, somewhat rare and aggressive. It frequently targets the mandible, but seldom the maxillary.

CASE STUDY

The present study reports the first case of left maxillary sinus fibroma treated at the Kara Teaching Hospital in North Togo. It occurred in a 29-year-old patient who experienced slow-growing tumefaction of the left maxillary sinus, resulting in deformation of the left side of the face in the maxillary region and ipsilateral nasal obstruction. Orthopantomography showed a displacement of teeth 21, 22, and 23 with an abnormal degree of opacity at the dental roots. The CT scan of the nose and sinuses revealed a tumorous lesion of expanding bony density increasing in volume at the outer wall of the left maxillary sinus, of regular shape that contained microscopic calcifications, extending into the ipsilateral orbital floor and pushing the surrounding soft tissues forward without invading them. The histopathological examination of the tumor confirmed the diagnosis of ossifying fibroma.

DISCUSSION

Ossifying fibroma or fibrous osteoma is a rare and benign lesion developing insidiously with a polymorphous aspect. Of unknown etiology, most frequently located in the mandible, it is differentiated from other types of fibroma in its clinical, radiological, and histological aspects. However, only examination of the gross specimen can provide the final diagnosis. Treatment requires surgery.

CONCLUSION

Surgical treatment entailed the complete macroscopic enucleoresection. Recovery has been favorable at 2 years of follow-up.

Unilateral maxillary swelling: a retrospective study

Unilateral maxillary swelling is a rare condition, however we being in tertiary care centre did see a large number of these cases. All patients presenting with unilateral maxillary seen during the last 3 years were included in this retrospective study and evaluated concerning histories, diagnostic and therapeutic approaches and achieved outcomes. A total of 31 patients were seen during this period. 27 of these were benign lesions and were subdivided as follows: odontogenic cystic lesions (11/27), fibro-osseous lesions (8/27), secondary to extensive allergic fungal sinusitis (5/27) and mucocele (2/27). The remaining five were malignant lesions, two each were squamous cell cancer and adenocarcinoma of the maxillary sinus, and one was rhabdomyosacroma. All patients received treatment with due merit of the underlying etiology. Understanding and recognizing key diagnostic features helps in appropriate management and reducing morbidity.

Cranial ossifying fibroma causing visual disorder

Fibrous lesions of the head and the maxillofacial region are generally slow-developing benign tumors that may aggressively take course in clinical terms. These locally destructive lesions show a high recurrence rates unless they are removed gross totally. Sarcomatoid degeneration is also reported to develop in recurring lesions. Difficulties in the diagnosis, classification, and treatment make this entity complex for several years. These tumors are frequently seen among children and young adults. The maxilla and the mandibula are the 2 most common sites that the tumor originates. In our article, we discuss a 59-year-old man whose condition was diagnosed as an ossified fibroma revealing craniofacial extension. Accompanied by literature findings, it has been underlined that, as well as with the pathologic criteria, clinical features and radiologic images should be evaluated together for a specific diagnosis in fibrous lesions.

[Pedunculated osteoma of the frontal sinus]

Osteoma, the most frequent tumor of the paranasal sinuses (PNS), is often asymptomatic. Men are more commonly affected than women. A 52-year-old patient complained of increasing incidence of headaches following the resolution of frontal sinusitis. Computer tomography demonstrated a pedunculated osteoma of the frontal sinus. Histomorphologically, PNS osteomas usually show cortical bone differentiation with sparse medullary space and a lamellar configuration. At 6 months following surgical resection, the patient was still symptom-free.

Management of juvenile ossifying fibroma in the maxilla and mandible

We present three cases with juvenile ossifying fibroma. Two occurring in the maxilla, and one in the mandible. All three cases presented with a major swelling in the face. After clinical and radiological evaluation the lesions were surgically excised and sent for histopathological evaluation. Two histological types of juvenile ossifying fibroma were found, the psammatous type in two cases and the trabecular pattern in one case. Although juvenile ossifying fibroma is an uncommon clinical entity, its aggressive local behaviour and high recurrence rate mean that it is important to make an early diagnosis. It is also important to apply the appropriate treatment and to follow-up the patient closely over the long term. This report describes the diagnosis and treatment of juvenile ossifying fibroma in the maxilla and the mandible. It also emphasizes the importance of considering the less aggressive options as a first line of treatment before choosing the aggressive approach when dealing with children.

[CT and MRI of intrinsic space-occupying lesions of the bony skull base]

Intrinsic bony lesions of the skull base are diseases which arise within the bones forming the skull base. Mainly they are bone tumours and tumour-like lesions. With the exception of osteomas of the paranasal sinuses and exostoses of the external auditory canal, these lesions occur rarely. This article gives an overview of the appearance of the most common primary bony skull base masses in CT and MRI. From the authors' point of view these are fibrous dysplasia, chordomas, chondrosarcomas, Langerhans cell histiocytosis and multiple myelomas, which must be differentiated from pseudolesions. The possibilities of CT and MRI in making a specific diagnosis, differential diagnosis and the kind of making the final diagnosis are described.

Fibro-osseous lesion of the middle turbinate: ossifying fibroma or fibrous dysplasia?

Benign fibro-osseous tumours of the head and neck region seldom appear in the midface and nasal cavity. Correct differential diagnosis of fibro-osseous tumours is crucial for adequate therapy, as their clinical aggressiveness seems to differ. The rather uncommon case of a 14-year-old boy with a tumour of the middle turbinate is presented. The radiologic appearance of the tumour, on computed tomography and magnetic resonance imaging scans, was consistent with fibrous dysplasia. Angiography revealed extensive vascularisation of the tumour from both the internal and external carotid arteries. To avoid ipsilateral blindness following embolisation, a superselective embolisation of the supplying blood vessels was performed. The tumour was completely resected via an endoscopic approach. Histopathology revealed an ossifying fibroma. This case emphasises the importance of interpretation of the clinical, radiological and histological features before planning definitive treatment. Moreover, when fibro-osseous tumours are suspected, the possibility of extensive, complicated vascularisation must be considered. This case underwent radical resection, with no recurrence after four years' follow up.

Psammomatoid ossifying fibromas: immunohistochemical analysis and differential diagnosis with psammomatous meningiomas of craniofacial bones

OBJECTIVE

To clarify the role of immunohistochemistry in the diagnosis of psammomatoid ossifying fibroma (PSOF), conventional cemento-ossifying fibroma (COF), and psammomatous meningioma (PM) of the craniofacial skeleton.

STUDY DESIGN

The histology and immunohistochemistry of 4 PSOFs, 6 COFs, and 7 PMs was studied. Antibodies included EMA, cytokeratins, smooth muscle actin (SMA), desmin, vimentin, CD34, CD10, S-100 protein, and glial fibrillary acidic protein (GFAP).

RESULTS

All PSOFs showed multiple round ossicles homogeneously distributed within a fibroblastic stroma. Psammomatous meningiomas had meningothelial features. All tumors, except 1 COF, were positive for EMA. All of them expressed vimentin, and none showed cytokeratins. Staining for SMA and S-100 protein was variable. CD10 was positive in all cases except 2 meningiomas. CD34 and GFAP stained only 1 case of meningioma each.

CONCLUSIONS

The diagnosis of PSOF should rest on histologic features. An incorrect diagnosis of meningioma based on the expression of EMA should be avoided.

Role of MR and CT in the paranasal sinuses

This article discusses the benefits and drawbacks of MR imaging and computed tomography as they relate to sinus disease.

Paediatric fibro-osseous lesions of the nose and paranasal sinuses

OBJECTIVE

The term "fibro-osseous lesion" is a generic description for a group of lesions involving the paranasal sinuses and anterior skull base. We aim to improve understanding of the clinical and pathological presentation of fibro-osseous lesions in children.

METHODS AND RESULTS

We report two cases of aggressive "fibro-osseous" lesions arising from paranasal sinuses and anterior skull base in childhood that were successfully managed surgically. We compare our case reports with a review of the available literature and evaluate the management of these lesions.

CONCLUSIONS

The clinical behaviour and radiological features of fibro-osseous lesions is variable. Aggressive lesions require a radical surgical approach to ensure complete excision, in spite of an increase in associated morbidity. Incomplete excision of aggressive lesions may result in disease recurrence with severe morbidity or mortality. In contrast a slowly progressive lesion often does not warrant extensive surgical excision. Understanding the nature of fibro-osseous lesions facilitates appropriate clinical management.

Opaque maxillary antrum: a pictorial review

The demonstration of an opaque antrum on a plain radiograph or cross-sectional imaging leads to consideration of an extensive differential diagnosis. Relevant clinical details narrow the differential and include the patient's age, signs and symptoms, a history of recent trauma, prior surgery or dental treatment. Computed tomography remains the most useful technique in coming to a specific diagnosis. Magnetic resonance imaging adds specificity in a few selected situations and is required in conjunction with CT in the staging of malignant tumours.

Endoscopic surgery for fibrous dysplasia of the sinonasal tract in pediatric patients

Fibrous dysplasia (FD) is a non-neoplastic, expansile lesion of unknown origin. In about one-fourth of cases this disorder affects the head and neck area, where the mandible and maxilla are the most frequently involved sites. Its localization to the ethmoid is a rare event. Since the disease slowly progresses, its management is delayed until significant clinical symptoms or non-well-tolerated aesthetic deformities are present. When required, surgery is the treatment of choice. Several external procedures have been used to manage the lesion, but recently, more conservative transnasal approaches have been proposed. We report the history of a 6-year-old boy with fibrous dysplasia of the ethmoid labyrinth that underwent successful transnasal endoscopic removal. Furthermore, an analysis of the literature is presented with particular emphasis on clinical picture, diagnosis, and treatment of this rare illness.

Ossifying Fibroma of the Skull: Interactive Image-Guided Minimally Invasive Localization and Resection

Ossifying fibroma is a benign fibro-osseous tumor commonly affecting the craniofacial bones. It is considered to be a locally aggressive and quickly expansible bone lesion. Because of its aggressive nature and high recurrence rate, early detection and complete surgical removal are essential. Usually, these lesions are excised extensively by craniectomy, and bone loss is reconstructed by cranioplasty using acrylic resin or titanium implants. Alternatively, in the management of skull-ossifying fibroma, an image-guided technique using surgical navigation may provide precise information about localization, enabling complete removal, thereby operating with minimal exposure and within narrow resection borders and avoiding significant bone deformity. A 39-year-old male patient with a history of renal cell carcinoma was admitted to our hospital because a radionuclide scintigraphic bone scan revealed increased uptake in a small area located at the left lateral skull bone. The high-resolution computed tomography scan showed that the lesion was located inside the diploe, destroying the inner table of the calvarium. The patient underwent minimally invasive bone lesion removal using an interactive image-guided approach. Complete resection of the neoplastic lesion was achieved. The histopathological examination revealed an ossifying fibroma. The postoperative course was uneventful, and the patient was discharged 3 days after intervention. To date, there has been no evidence of local recurrence. Interactive multimodal planning and intraoperative image guidance offer an interesting approach for biopsy and minimally invasive removal of small ossifying fibroma lesions of the skull, especially in less accessible locations.

Fibrous dysplasia of ethmoid - a rare presentation

Monostatic fibrous dysplasia involving th ethmoid is one of the rarest lesions. The clinico-pathologhical featutres and management are described.

Fibro-osseous lesions of the maxillo-ethmoid complex with orbital involvement

Fibro-osseous lesions involving the maxillo-ethmoid complex are rare. Extensive lesions leading to proptosis are rare still. We report here 22 cases of fibro-osseous lesions with orbital involvement. CT scan was the mainstay of radiological investigation. Transfacial excision was done in all cases, except three which necessitated a cranio-facial resection. Surgery resulted in significant reduction of proptosis and improved cosmesis in all cases. In three instances, a sliver of the tumor tissue was left behind due to its proximity to the dura or optic nerve. Two of these cases however went on to develop subsequent visual loss secondary to disease progression. Six cases necessitated revision surgery for residual or recurrent lesion.Disease extension to the proximity of vital structures should be excised as continuing tumor growth may prove unsafe.

Multiple cemento-ossifying fibroma: report of an 18-year follow-up

Multiple cemento-ossifying fibroma is a very rare jaw lesion. A unique case is reported involving a 43-year-old Korean woman with rapidly growing, multiple cemento-ossifying fibromas in all four quadrants over an 18-year period which resulted in severe facial deformity and orbital compression.

Benign fibro-osseous lesions: a review of current concepts

The benign fibro-osseous lesions (BFOL) represent a clinically diverse group of disorders of bone that share similar histopathologic features. As a group, they are relatively common in the craniofacial complex, especially the jaws. Although the general concept of BFOL is relatively well known, specific diagnostic interpretation of individual cases is often challenging. New concepts and controversies have arisen over the past 10 to 15 years regarding classification and diagnostic criteria. However, among the new theories and contentions, there is now essential agreement that the osseous dysplasias represent a single disease process, while the so-called "juvenile active ossifying fibroma" and other "aggressive," "active," "psammomatoid" ossifying/cementifying fibromas remain controversial. This review is presented to update the surgical pathologist on the various entities comprising the spectrum of BFOL and to examine the criteria for their diagnosis.

Fibrous dysplasia with cystic appearance in maxillary sinus

Fibrous dysplasia (FD) in the paranasal sinuses is uncommon, and its management may be difficult. We report the case of a 25-year-old female with FD exhibiting a cystic appearance in the maxillary sinus. The patient had been complaining of facial swelling for few years. Imagery study showed a cystic lesion and dense bone changes in the maxillary bone. Inferior meatal antrostomy with a nasal endoscope failed to confirm a histological diagnosis. After a 3-year follow-up, the degree of facial swelling was unchanged, and the patient underwent middle meatal antrostomy and was diagnosed with FD.