[Osteosarcoma Secondary to Polyostotoic Fibrous Dysplasia of the Ribs].

Sarcomatous transformation of fibrous dysplasia is extremely rare. We present the case of a 54-yearold man with multiple rib masses, multiple enlarged lymph nodes throughout the body, and multiple osteolytic lesions on computed tomography( CT). A positron emission tomography( PET) scan showed abnormal enhancement in each. A needle biopsy of the right supraclavicular fossa lymph node revealed sarcoidosis. Considering the possibility of malignancy associated with sarcoidosis, a rib tumor resection and mediastinal lymph node biopsy were performed to confirm the diagnosis of the rib lesion. The pathology results showed that the rib mass was a low-grade central osteosarcoma and the mediastinal lymph node was sarcoidosis. The distribution of the lesions was consistent with osteosarcoma secondary to multiple fibrous bone dysplasia. As the osteosarcoma was low grade, the patient was followed up. Three years after surgery, there was no increase in residual disease.

Cystic degeneration of the fibrous dysplasia presenting with loss of vision.

Cystic degeneration of the fibrous dysplasia is a very rare clinical condition and may present with loss of vision when it involved the skull base. A 12-year-old female child presented with an enlargement of the skull. She was diagnosed as large skull base and skull vault tumor. She underwent partial removal of the tumor, and custom-made titanium implant was inserted. The diagnosis was fibrous dysplasia. Two years after the initial diagnosis, she presented with total loss of vision at her right eye. Radiological imaging confirmed the cystic degeneration within the tumor. She re-operated and the cyst fluid was evacuated in association with the removal of cyst wall. The diagnosis was the cystic degeneration of the fibrous dysplasia. Her vision was improved a few days after the surgery. Fibrous dysplasia of the skull base should be closely followed-up in order to prevent severe visual complications.

Fibrous dysplasia with aneurysmal bone cyst-like change occurring in pediatric orbit: case report and literature review.

PURPOSE: We report a case of fibrous dysplasia (FD) with aneurysmal bone cyst (ABC)-like change in a child with orbital involvement, review the related cases, and discuss clinical features, therapy, and prognosis of this disease. CASE PRESENTATION: A 10-year-old girl had right proptosis (degree of exophthalmos: OD 16 mm, OS 13 mm) and limited vision (visual acuity: OD 1.0, OS 0.8) without trauma. Preoperative CT showed a 5.0*4.3 cm right-sided crania-orbital communicating tumor. MRI indicated a well-defined multicystic mass with scattered fluid levels and soap bubble-like alterations. The child underwent total tumor resection and orbital parietal titanium mesh reconstruction. At 20 months of follow-up, the child has recovered from ocular problems, and the tumor has not recurred. CONCLUSION: FD combined with ABC rarely occurs in orbit and generally begins with ocular symptoms. The etiology is uncertain. Early diagnosis and surgery are essential. Complete resection is suggested whenever possible because residual lesions may recur.

Craniofacial Fibrous Dysplasia in Fronto-Orbital Region: A Single-Center Retrospective Study of 38 Cases.

OBJECTIVE: This study presents the clinical characteristics, imaging manifestations, and surgical experience in 38 patients diagnosed with craniofacial fibrous dysplasia in fronto-orbital region (foFD). METHODS: We retrospectively analyzed the clinical data from 38 patients who had surgery for foFD. The surgical procedure typically involved extensive tumor removal, followed by immediate reconstruction of the frontal bone and orbit using synthetic materials. Additionally, 9 patients underwent simultaneous microscopic decompression of the optic canal. RESULTS: Common clinical manifestations included progressive fronto-orbital bone deformity (35), proptosis (28), orbital dystopia (21), and visual impairment (9). The disease primarily affecting the frontal bone (38), the sphenoid bone (28), and the ethmoid bone (24). The optic canal was involved in 9 patients with functional impairment. Computed tomography scans in all 38 cases revealed satisfactory repair material positioning and complete resolution of frontal deformities. Among the 9 patients who underwent optic canal decompression, 7 experienced partial recovery of visual acuity after surgery. CONCLUSIONS: In the surgical treatment of foFD, it is crucial to achieve maximal bone resection and repair skull defects, while decompressing the optic canal can provide significant benefits for patients with decreased visual function preoperatively. The use of preformed artificial materials offers advantages in aesthetic restoration after lesion excision.

Computer simulation-assisted reconstruction of severe bone defects in adults players

Background:This retrospective study focuses on the application of computer simulation in reconstructing severe bone defects in adult players with fibrous dysplasia. Conducted from August 2017 to December 2020, the study analyzed medical records of nine patients treated in our department. The approach involved importing image data into a computer to reconstruct models of affected limbs, enabling precise lesion locationidentification for curettage, bone grafting calculations, and internal fixation matching. The study included nine adult patients, suffering from either monostotic or polyostotic forms of severe fibrous dysplasia, with lesions located in the humerus, femur, and tibia. The results showed that this method can shorten surgery time, minimize intraoperative trauma, and enhance the effectiveness of bone reconstruction. The average follow-up period was 32.27 months, with the MSTS score averaging 21.2 points and Shin's imaging scoring system for bone grafting scoring an average of 13.5 and 14.3 at the 1-and 2-year post-operation marks, respectively. Despite two patients experiencing complications, this technique demonstrates promise in managing severe bone defects in adults, particularly in sports-related contexts (AU)

Case Report Of Rib Polyostotic Fibrous Dysplasia.

Polyostotic fibrous dysplasia is a rare benign asymptomatic tumour of the ribs not requiring surgery on most occasions. We present here a case with left 10th and 11th rib fibrous dysplasia which was causing a hinderance to the Urologist for renalstone extraction. Therefore the 10th and 11th ribs were excised followed by chest wall reconstruction.

Secondary aneurysmal bone cyst of the frontal bone with fibrous dysplasia showing rapid expansion: a case report.

A 19-year-old woman presented with swelling of the left forehead without pain. She did not have any relevant past or family history. Computed tomography showed destruction of the outer cortex of the frontal bone. A solitary mass lesion with a fluid collection was detected with magnetic resonance imaging. Because the swelling of the left forehead had enlarged rapidly with osteolytic changes, surgical removal of the lesion was performed. The lesion appeared to be enveloped in a fibrous capsule. The soft lesion was removed from the frontal bone. The outer frontal bone was absent, although the inner frontal bone was preserved. Then, the frontal bone was resected with margins from the edge of the erosion. The dura mater under the lesion was intact. A cranioplasty was performed using titanium mesh. On histological examination, the trabecular bones revealed irregular shapes and arrangements, indicating fibrous dysplasia. There was a continuous high-cell-concentration pathological lesion outside the fibrous dysplasia. There were numerous cells, such as mononuclear cells, osteoclast-like multinucleated giant cells, foam cells, and red blood cells. The osteoclast-like multinucleated giant cells and other cells did not show significant nuclear atypia. Immunostaining with H3.3G34W was negative, and the ubiquitin-specific peptidase 6/Tre-2 gene showed no rearrangements. The histopathological diagnosis was secondary aneurysmal bone cyst with fibrous dysplasia. Additional postsurgical therapy was not performed. There has been no evidence of recurrence of the lesion for two years.

Computer-guided contouring of craniofacial fibrous dysplasia involving fronto-orbital or fronto-cranial region using patient specific surgical depth guide: A prospective case series.

The aim of this study was to introduce a new computer guided technique for debulking and contouring the craniofacial fibrous dysplasia involving the fronto-orbital and fronto-cranial regions. Computer-guided contouring was performed using a modified patient-specific surgical depth guide for six patients with craniofacial fibrous dysplasia involving the fronto-orbital and fronto-cranial regions. Virtual planning was performed to determine the desired amount of bone removal and construct the patient-specific surgical depth guide. Then, the guide was printed using rapid prototyping. In the surgical theatre, the guide was seated in position. Implant drills were inserted through the created depth holes according to the planned fixed depth to create depth holes. Finally, the bone in between the created holes was removed using cutting discs, bone chisels and surgical burs. Satisfaction with facial aesthetics was evaluated by the patients using a Likert scale, and by the surgeons using the Whitaker rating scale. The surgical procedures were uneventful for all the patients. All the patients were satisfied with the post-operative facial esthetics and categorized as category I Whitaker rating scale. Patient-specific surgical guide technique for recontouring of fronto-orbital and fronto-cranial fibrous dysplasia can be considered an accurate substitution technique that overcomes the drawbacks of the unpredictable conventional one. Further investigations are required.

[Aesthetic rehabilitation of a case of maxillary fibrous dysplasia in a child]. / Réhabilitation esthétique d'un cas de dysplasie fibreuse maxillaire chez l'enfant.

Fibrous dysplasia (FD) is a rare, congenital, benign bone disorder in which healthy bone tissue is replaced by abnormal scar-like (fibrous) connective tissue. The lesions may affect one or more bones, including the jawbones. A 13-year-old girl visited the dentist for failed eruption of her left maxillary permanent teeth and facial asymmetry. Radiological analysis revealed impactions of the permanent teeth in hypertrophic, hyperdense, weakly trabeculated bone tissue. To restore the aesthetics of the smile, a treatment combining decoronation and bonded restorations was performed. FD enlargement would slow down after puberty, allowing for long-term therapies. But there is no information about implantology in this type of bone lesion. The aesthetic and functional consequences of a maxillary FD should be managed as soon as possible. Treatment involves a multidisciplinary team and follow-up care into adulthood.

The Virtual Surgical Management of Facial Fibrous Dysplasia.

PURPOSE: Fibrous dysplasia (FD) is a benign condition, which is characterized by the replacement of normal bone with fibrous tissue and the deposition of woven bone in an irregular manner. Surgical resection, careful corrective osteotomies as debulking, and recontouring procedures are frequently performed, but can be complicated by postoperative regrowth of the lesion. The main aim of this study was to introduce a computer-guided technique for a predetermined technique of bone contouring of craniofacial FD involving the facial bones. METHODS: This case report was conducted on an 18-year-old girl complaining of unilateral craniofacial dysplasia. Upon clinical examination and radiographic examination, a customized computer-generated bone contouring guide was designed using virtual surgical software for accurate contouring of excess bone in the cranial vault and frontal bone. This guide was virtually designed after importing the multislice computerized tomography scans into the virtual surgical planning software. It was generated based on the mirroring option of the unaffected normal side along the median sagittal plane. In the surgery, the guide was seated in place and 5 mm implant drills were inserted through the guide depth holes. Bone removal was made using surgical burs connecting the guiding depth holes. RESULTS: At the end of the follow-up, the patient showed acceptance of her external appearance with no signs of infection or dehiscence. CONCLUSION: This patient-specific cutting guide shows a promising solution for preplanned bone removal in cases with unilateral craniofacial FD.

Intracranial Dermoid in Patients With Fibrous Dysplasia.

OBJECTIVES: Intracranial epidermoid cyst (EC) and craniofacial fibrous dysplasia (CFD) were histogenetically different rare congenital benign diseases. The coexistence of intracranial EC and CFD was extremely rare and had not been reported yet. MATERIALS AND METHODS: We retrospectively reviewed the clinical and radiologic information of 3 patients diagnosed with concomitant EC and CFD at Beijing Tiantan Hospital from January 2003 to January 2021 and summarized their clinicopathological features, treatment modalities, and outcomes. In addition, we performed a systematic review of cases of the coexisting intracranial EC and other intracranial abnormalities to explore the potential connections. RESULTS: There were 2 women and 1 man with the mean age of 31 years old. Satisfactory resection was fulfilled for all the 3 ECs. CFD, however, was managed with watchful waiting. During the mean follow-up time of 58 months, all the ECs showed no sign of recurrence, and all the CFD lesions remained stable. Two EC specimens underwent genetic study, showing no GNAS mutations and negative G s α protein expression. In the literature review of concomitant intracranial EC and other intracranial abnormalities, 23 studies were included. With 5 reported cases, the intracranial aneurysm was found to be the most common intracranial disease that coexisted with EC. CONCLUSIONS: The coexistence of intracranial EC and CFD was extremely rare. However, no convincing mechanism and evidence underlying such coexistence had been found. To provide more profound understanding about these 2 diseases and improve diagnosis and treatment strategy, further research and verification should be considered.

A Novel Bone Contouring Technique Using Multiple Tangential Shaving for Conservative Management of Craniofacial Fibrous Dysplasia.

This study aimed to propose a novel surgical technique, named multiple tangential shaving of bone contour, for the conservative management of craniofacial fibrous dysplasia. We retrospectively reviewed 17 patients who underwent conservative management of craniofacial fibrous dysplasia using multiple tangential shaving technique between July 2005 and December 2020. Demographics, tumor characteristics, and surgery-related factors were investigated. All patients underwent preoperative (T0) and postoperative computed tomography scans taken at least twice within 1 month for immediate assessment (T1) and at least 12 months postoperatively for long-term assessment (T2). Clinical outcomes, including tumor recurrence, perioperative complications, and physician measure of esthetic outcomes (Whitaker score), were investigated. This technique was applied for contouring of the zygomatic-maxillary and calvarial bone for patients aged between 16 and 60 years (mean age: 26 y). The mean±SD tumor volume reduction was 15.5±8.95 cm 3 , and the postoperative mean±SD tumor growth rate was 5.52±6.26% per year. Satisfactory outcome was obtained in terms of esthetics with a mean±SD Whitaker score of 1.41±0.62. Patients required a mean operation time of 1.67±0.43 hours and a mean number of shaving operations of 1.35±0.61 during the follow-up period. Five of 17 patients required reoperation because of the tumor recurrence (N=4) and to correct new-onset diplopia after surgery (N=1). In conclusion, the multiple tangential shaving technique allows an easy approach for conservative management of craniofacial fibrous dysplasia. An acceptable rate of tumor recurrence and esthetic outcomes can be obtained by selecting the appropriate candidate for a conservative approach.

Surgical management of syndromic versus non-syndromic craniofacial fibrous dysplasia: a systematic review and meta-analysis.

The main purpose of this study was to identify an algorithm for the surgical management of fibrous dysplasia in syndromic (McCune-Albright syndrome) and non-syndromic patients (monostotic and polyostotic subtypes). The secondary objectives were to assess the prevalence of affected craniofacial bones and the main clinical presentation. The authors performed a systematic review and meta-analysis by conducting a comprehensive electronic search from 1 January 2000 to 31 December 2019. A total of 1260 patients were included. The maxilla was the most affected facial bone (41%) (p<0.001, CI 38.3 to 43.8) and facial asymmetry was the chief complaint (p<0.001, CI 31.7 to 37.1). Conservative surgery registered higher recurrence rates than radical resection in both syndromic (84%) (p<0.001, CI 70.9 to 92.8) and non-syndromic patients (26%) (p<0.001, CI 21.8 to 30.6). Compared with prophylactic decompression, therapeutic optic nerve decompression (OND) showed better postoperative outcomes in both syndromic (p=0.9, CI 18.6 to 55.9) and non-syndromic patients (p=0.09, CI 9.3 to 28.4). Watchful waiting showed excellent results in both subgroups when asymptomatic (p<0.001). Syndromic and non-syndromic patients share the same treatment strategies. Radical resection is the preferred surgical technique to eradicate the disease, but it is often difficult to perform due to the extent and location of the disease. Furthermore, the authors advise early therapeutic over prophylactic OND to prevent optic nerve atrophy. Asymptomatic patients should be managed expectantly. Finally, medical management helps reduce the symptoms of bone pain (p=0.02 in non-syndromic and p<0.001 in syndromic patients).

A Multimodal Approach to Huge Fibrous Dysplasia With Ocular Symptoms Using a Navigation System and Endoscope.

BACKGROUND: Fibrous dysplasia (FD) is a rare sporadic benign disease, which involves from single to several bones with unilateral distribution. Recently, image-based surgical navigation systems have played a significant role in surgical process on neurological and orthopedic operations. However, because an intraoral approach can visualize the field for maxillary surgery, there are few cases using endoscopes for excision of FD. Even though, a huge mass involving posterior side of maxillary sinus can be assisted with an endoscope to protect essential structures. To the best of our knowledge, this is the first report of plastic and reconstructive surgeons to perform the operation of a huge FD with both an endoscope and a navigation system. METHODS: Preoperative computed tomography scan and magnetic resonance imaging was performed for precise diagnosis and setting the navigation system (Medtronic Navigation, Louisville, CO). The main problem of the patient was exophthalmos and decreased visual acuity, the authors decided to remove the mass involving the intraorbital portion and sphenoidal portion. Moreover, the mass was extending to intracranium, cooperation with the department of neurosurgery and otolaryngology was planned. The tumor reached by the endoscope was resected as much as possible. During the excision of the sphenoidal portion by the head and neck surgeon of the department of otolaryngology, cerebrospinal fluid leakage was observed and repaired by the neurosurgeon. RESULTS: The exophthalmos measured by Hertel exophthalmometry was reduced only 1 mm, however, gross morphology of the patient was totally changed after the operation. Visual acuity of the right eye was improved from 0.3 to 0.9. The patient was followed up about 6 months and had a seizure event at 2 weeks after the surgery. Afterwards, the symptom has been well controlled by the medication. CONCLUSIONS: This multimodal approach offers a safe, rapid surgical aid in treating huge lesions involving orbital and intracranial area.

Pediatric Cases of Recurrent Skull Giant Osteoma Misdiagnosed as Fibrous Dysplasia.

ABSTRACT: Osteomas are benign mature bone tumors that typically arise in the skull. Osteomas larger than 3 cm in diameter are considered giant osteomas. Giant osteomas of the skull vault are very rare, especially in children; therefore, only a few cases have been reported in the literature. Although osteomas are usually asymptomatic, a large skull mass can cause headache, as well as esthetic disfigurement of the forehead. it can be misdiagnosed as other conditions, such as fibrous dysplasia, ossifying cephalhematoma, or other malignant bone tumors. Herein, the authors report 2 rare pediatric cases of giant osteomas mimicking fibrous dysplasia and their successful surgical excision. These cases showed good results without recurrence or complications on long-term follow-up after complete excision.

Fibrous dysplasia: rare manifestation in the temporal bone / Displasia fibrosa: manifestação rara no osso temporal

Abstract Introduction: Fibrous dysplasia is a benign disorder, in which normal bone is replaced by fibrosis and immature bone trabeculae, showing a similar distribution between the genders, and being more prevalent in the earlier decades of life. Fibrous dysplasia of the temporal bone is a rare condition, and there is no consensus as to whether it is more common in monostotic or polyostotic forms. External auditory meatus stenosis and conductive dysacusis are the most common manifestations, with cholesteatoma being a common complication, whereas the involvement of the otic capsule is an unusual one. Surgical treatment is indicated to control pain or dysacusis, otorrhea, cholesteatoma, and deformity. Objectives: To describe the clinical experience of a tertiary referral hospital with cases of fibrous dysplasia of the temporal bone. Methods: Sampling of patients diagnosed with fibrous dysplasia of the temporal bone, confirmed by tomography, treated at the pediatric otology and otorhinolaryngology outpatient clinics, between 2015 and 2018. The assessed variables were age, gender, laterality, external auditory meatus stenosis, deformity, hearing loss, presence of secondary cholesteatoma of the external auditory meatus, lesion extension and management. Results: Five patients were included, four females and one male, with age ranging from 13 to 34 years. Three had the polyostotic form and two the monostotic form of fibrous dysplasia of the temporal bone. Four patients had local deformity and external auditory meatus stenosis, two of which progressed to cholesteatoma. All patients showed some degree of hearing impairment. All had preserved otic capsule at the tomography. Two patients are currently undergoing clinical observation; two were submitted to tympanomastoidectomy due to secondary cholesteatoma; one was submitted to lesion resection, aiming to control the dysacusis progression. Conclusion: Five cases of fibrous dysplasia of the temporal bone were described, a rare disorder of which the otologist should be aware.

Resumo Introdução: Displasia fibrosa é uma desordem benigna, na qual o osso é substituído por fibrose e trabeculado ósseo imaturo, com distribuição semelhante entre sexos, mais comum nas primeiras décadas de vida. O acometimento do osso temporal pela displasia fibrosa é raro, não há consenso se é mais comum nas formas monostóticas ou poliostóticas. Estenose do meato acústico externo e disacusia condutiva são as manifestações mais comuns. Colesteatoma é também uma complicação comum e o acometimento da cápsula ótica incomum. O tratamento cirúrgico está indicado para controle de dor ou disacusia, otorreia, colesteatoma, deformidade. Objetivos: Descrever a experiência clínica de hospital terciário de referência com casos de displasia fibrosa do osso temporal. Método: Amostragem dos pacientes com diagnóstico de displasia fibrosa do osso temporal, confirmado pela tomografia, atendidos nos ambulatórios de otologia e otorrinolaringologia pediátrica, entre 2015 e 2018. As variáveis avaliadas foram idade, gênero, lateralidade, estenose do meato acústico externo, deformidade, perda auditiva, presença de colesteatoma secundário de meato acústico externo, extensão da lesão e conduta adotada. Resultados: Foram incluídos cinco pacientes, quatro do sexo feminino e um masculino, de 13-34 anos. Três apresentaram a forma poliostótica da displasia fibrosa do osso temporal e dois a forma monostótica. Quatro apresentaram deformidade local e estenose do meato acústico externo, dois desses evoluíram com colesteatoma. Todos manifestaram algum grau de comprometimento auditivo. Todos apresentaram cápsula ótica preservada na tomografia. Duas pacientes estão em observação clínica; duas foram submetidas a timpanomastoidectomia devido a colesteatoma secundário; um foi submetido a ressecção da lesão para controle de progressão da disacusia. Conclusão: Foram descritos cinco casos de displasia fibrosa do osso temporal, desordem rara para a qual o otologista deve estar atento.

Long-Term Results of Fibrous Dysplasia of the Paranasal Sinuses.

INTRODUCTION: Fibrous dysplasia (FD) is a benign, idiopathic skeletal disorder, in which the normal bone and marrow are replaced by fibrous tissue and immature woven bone. The authors aim to analyze the long-term results of patients diagnosed with FD of the paranasal sinuses via imaging or surgical biopsy. METHODS: The authors retrospectively enrolled 21 patients with FD of the paranasal sinuses from 2006 to 2021. RESULTS: The mean age at the time of diagnosis of FD of the paranasal sinuses was very high at 45.9 years. The most common site ofoccurrence was the sphenoid sinus (71.4%). During the mean follow-up period of 52.8 months, there was no significant change in the size of FD of the paranasal sinuses, and there was no worsening of symptoms or complications. Endoscopic sinus surgery was performed in 16 patients (76.2%), of which 13 underwent only biopsy and 3 underwent partial resection. CONCLUSIONS: The most common site of FD of the paranasal sinuses was the sphenoid sinus, and the age at diagnosis was higher thanthat of patients with FD at other sites. Observation with serial radiologic examinations is recommended for asymptomatic FD of the para-nasal sinuses.

Intramedullary Nailing for Lower Limb Polyostotic Fibrous Dysplasia in Children: A Long-term Follow-up Study.

BACKGROUND: In children, intramedullary nailing (IN) has been proposed as the best treatment when the femur and tibia are totally affected by fibrous dysplasia (FD). However, in younger children IN must be repeated to maintain stabilization of the affected skeletal segment during growth. We report the long-term results in a cohort of patients in whom more than two-thirds of cases had IN repeated during growth. METHODS: Twenty-nine femurs and 14 tibias totally affected by FD were treated by IN in 21 patients with polyostotic FD and McCune-Albright syndrome. Thirteen patients with 35 femoral and tibial deformities had a painful limp whereas 8 presented fractures. The patients had their first IN at a mean age of 9.26±2.68 years (range: 4 to 14 y). IN was repeated during growth in the younger patients, and all the patients underwent a mean of 2.13 femoral and 1.50 tibial IN per limb. The last IN was performed at a mean age of 16.42±1.95 years (range: 11 to 19 y). Titanium elastic nails and adult humeral nails were used in younger children, whereas adult femoral cervicodiaphyseal and interlocking tibial nails were used in older children and adolescents. At the latest follow-up, the patients were evaluated with a clinicoradiographic scale. All the data were statistically analyzed. RESULTS: The mean length of follow-up from the last IN was 6.47±3.10 years (range: 3 to 14 y), and the mean age of the patients at follow-up was 22.85±3.53 years (range: 14 to 29 y) when lower limbs were fully grown in all but 1 patient. Satisfactory long-term results were obtained in about 81% of our patients, while complications occurred in 32.5% of the 43 cases. CONCLUSION: Lower limb IN-that was repeated in younger children during growth-provided satisfactory long-term results in most of our patients, with fracture and deformity prevention and pain control, regardless of the high rate of complications that mainly affected the femoral cases. Missing scheduled follow-ups was the main predictor of a poor result. LEVEL OF EVIDENCE: Level IV-case series.

Navigation-guided nasal endoscopic surgery for acute vision loss caused by fibrous dysplasia: a case report and review of literatures.

BACKGROUND: Bone fibrous dysplasia is a benign disease of bone tissue dysplasia. Vision impairment is the commonest neurological complication of craniofacial fibrous dysplasia. Most of the vision loss caused by craniofacial fibrous dysplasia is usually a gradual process. Very few present with acute visual impairment as described in our case. CASE PRESENTATION: We report a patient with fibrous dysplasia presenting rapidly progressive visual loss in the left eye secondary to bone cyst formation. Transnasal endoscopic surgery guided by navigation with drainage and curettage of this bone cyst and orbital decompression resulted in progressive improvement in visual acuity that returned to normal 1 month post-operatively. CONCLUSIONS: In cases with acute visual loss due to fibrous dysplasia, emergency surgical treatment should be considered to preserve vision. In the surgical approach, navigation-guided nasal endoscopic surgery may be preferred because of its advantages.