Long-term outcome of optic nerve encasement and optic nerve decompression in patients with fibrous dysplasia: risk factors for blindness and safety of observation

Open and Endoscopic Endonasal Optic Nerve Decompression for Craniofacial Fibrous Dysplasia in an Adolescent: 2-Dimensional Operative Video

Craniofacial fibrous dysplasia (CFFD) is a benign, bony disease that may affect the skull base.1,2 Most cases are asymptomatic and observed; however, advanced disease can present with cranial neuropathy or craniofacial deformity requiring intervention.3-5 A 16-year-old adolescent girl with known CFFD involving the sphenoid and frontal bones with severe bilateral optic canal narrowing developed progressive right eye visual decline and frontal cosmetic deformity. Visual acuity worsened oculus dextrus (OD) to 20/30 with a new superior nasal scotoma and 20% loss in the retinal nerve fiber layer and remained oculus sinister (OS) 20/20. The patient was recommended a staged subfrontal craniotomy for right optic decompression and simultaneous correction cosmetic deformity followed by endonasal right optic decompression. On postoperative day one, visual acuity OD improved to 20/20; however, she developed OS visual decline to 20/800. Curiously, there were no episodes of intraoperative hypotension or additional iatrogenic compression. Use of methylprednisolone led to improvement OS 20/400. Given persistent visual decline, urgent second stage endonasal bilateral optic nerve decompression, rather than unilateral, was performed. Postoperatively, vision improved to OS 20/200. At one month, her vision improved to OD 20/15 and OS returned to 20/20 with a paracentral scotoma and 29% decline in left retinal nerve fiber layer with further improvement anticipated. This video describes a multidisciplinary, multistaged approach in treatment of optic nerve compression due to CFFD in addition to the management of unanticipated contralateral visual decline. The patient consented to the procedure and publication of her image. No Institutional Review Board/ethics committee approval was necessary for this case report.

The Natural History of Fibrous Dysplasia of the Orbit

BACKGROUND

Orbital fibrous dysplasia (FD) is a disease of disordered fibro-osseous proliferation secondary to altered osteogenesis, with potential sequelae including compressive neuropathy and irreversible vision loss. The purpose of this study was to evaluate the natural history and longitudinal outcomes of 37 patients with orbital FD who underwent stratified surgical management.

METHODS

All patients treated for FD from 2015 to 2021 were identified, yielding 185 patients, 39 with orbital involvement. Impressions from head computed tomographic scans were analyzed by a craniofacial radiologist to evaluate location and timing of tumor growth. Operative records were reviewed to determine surgical approach (partial excision/contouring, complete excision, or partial excision with optic nerve decompression).

RESULTS

The average patient age at diagnosis was 10.7 ± 4.5 years, and the average follow-up was 5.2 ± 4.7 years. Of the 37 patients with orbital involvement, 28 (75.7%) had optic canal involvement. Of those with optic canal involvement, 13 (46.4%) required partial excision with optic nerve decompression, whereas 15 (53.6%) did not. Of those without optic canal involvement, two patients (22.2%) underwent partial excision/contouring of the anterior orbit to correct dystopia and/or proptosis, and four patients (44.4%) underwent complete excision of the orbital component and reconstruction with bone graft or mesh. Younger age at diagnosis was associated with an increased number of surgical interventions ( P = 0.011), younger age at first optic canal decompression ( P = 0.003), and worse visual outcomes ( P = 0.009).

CONCLUSION

In the authors' cohort, patients diagnosed at a younger age required more operations, underwent decompression earlier, and had worse visual outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Craniofacial fibrous dysplasia: Systematic review of facial management

Craniofacial fibrous dysplasia (CFD) may be associated with major cosmetic or functional consequences. However, management recommendations for CFD are currently unavailable. Therefore, this systematic literature review aimed to review the existing approaches for CFD management and propose a management algorithm. The focus question was "What are the different options for CFD treatment and their complication rates?" The MEDLINE database was searched, and 33 articles evaluating a total of 1154 patients were reviewed. The bias assessment showed that 20 of the 33 studies had a high or intermediate risk of bias, mainly because of retrospective data collection and small patient numbers. Radical surgery showed a lower recurrence rate than debulking, but its use should be weighed against the morbidity caused by the reconstruction performed in this technique. Orbital decompression using a radical technique or debulking is effective in cases showing exophthalmos or dystopia. Surveillance is a viable option for asymptomatic and/or non-progressive lesions. In cases showing optic nerve compression, prophylactic decompression should be avoided, and decompression should be performed only when patients show diminished visual acuity or visual field defect. Although bisphosphonates have shown efficacy in pain management, their posology requires further discussion. A management algorithm is presented.

Long-term Outcomes Following Endoscopic Transnasal Surgery for Optic Neuropathy Due to Craniofacial Fibrous Dysplasia

OBJECTIVE

To investigate the feasibility of endoscopic transnasal optic canal decompression (ETOCD) guided by a navigation surgical system (NSS) for vision recovery in patients with compressive optic neuropathy (CON) caused by craniofacial fibrous dysplasia (CFD), and to explore the underlying cause of visual impairment.

METHODS

All patients underwent unilateral NSS-guided ETOCD and were followed up periodically for at least six months. Paired sample t-test and Pearson correlation analyses were used to compare continuous variables of the visual outcomes at the final review. A histopathological test of abnormal bone specimens was performed postoperatively.

RESULTS

Thirty-four patients were finally included, and all surgeries were uneventful. The best corrected visual acuity (BCVA) (logMAR units) decreased from 1.29 ± 0.80 preoperatively to 0.97 ± 0.78 at the last follow-up (p = 0.0012), improving in 28 patients (82.35%). The absolute value of mean defect (MD) significantly decreased (p < 0.001). Color vision was impaired in 17 patients preoperatively and improved in 6 patients. BCVA at the last follow-up was significantly correlated with preoperative BCVA, onset time, preoperative retinal nerve fibril layer thickness, and MD (all p < 0.05). Among 34 patients, 26 had a blunt bony process near the anterior foot of the optic chiasm. Of the total patients, 73.53% patients experienced bony fiber recurrence 6 months or earlier after surgery without visual loss.

CONCLUSION

NSS-guided ETOCD appeared to be safe and effective for visual recovery in patients with CON due to CFD, and early surgical intervention was critical for long-term recovery. Unbalanced compression of the optic canal by the blunt bony process may be a major cause of visual impairment.

LEVEL OF EVIDENCE

4 Laryngoscope, 2023.

Craniofacial Fibrous Dysplasia: Clinical and Therapeutic Implications

PURPOSE OF REVIEW

This study aims to review diagnosis, potential complications, and clinical management in craniofacial fibrous dysplasia.

RECENT FINDINGS

Fibrous dysplasia (FD) is a rare mosaic disorder in which normal bone and marrow are replaced with expansile fibro-osseous lesions. Disease presents along a broad spectrum and may be associated with extraskeletal features as part of McCune-Albright syndrome (MAS). The craniofacial skeleton is one of the most commonly impacted areas in FD, and its functional and anatomical complexities create unique challenges for diagnosis and management. This review summarizes current approaches to diagnosis and management in FD/MAS, with emphasis on the clinical and therapeutic implications for the craniofacial skeleton.

Autonomous growth hormone secretion due to McCune Albright syndrome in paediatric age group: an ominous triad

PURPOSE

The current study aimed to report cases of McCune Albright syndrome (MAS) with growth hormone (GH) hyper secretion along with a systematic review of literature to elucidate challenges and intricacies in its diagnosis and management.

METHODS

It was a single centre study carried out in individuals with MAS and autonomous GH secretion (AGHS). In addition, a systematic search of literature across three databases (PubMed, Scopus and EMBASE) was performed from inception until May 31, 2021 to identify cases of MAS with AGHS in the pediatric age group (<18 years).

RESULTS

Three cases from authors centre and 42 cases identified from systematic literature review were analysed. Precocious puberty was the most common presenting endocrinopathy seen in 56.8% (25/44) cases, followed by hyperthyroidism (10/45), hypophosphatemia (4/45), and hypercortisolism (2/45). Cranio-facial fibrous dysplasia (CFFD) was seen in all while polyostotic fibrous dysplasia and Café au lait macule was seen in 40/45 (88.9%) and 35/45 (77.8%), respectively. Pituitary adenoma (58.3% microadenoma) was localized in 53.3% (24/45) cases on pituitary imaging. Biochemical and clinical remission of AGHS was achieved in 61.5% (24/45) cases with medical therapy.

CONCLUSION

Diagnosing AGHS in MAS is challenging because of concomitant presence of CFFD, non-GH endocrinopathies associated height spurt and elevated serum IGF-1. GH-GTT should be performed in presence of elevated growth velocity and serum IGF-1 (>1 X ULN) despite adequate control of non-GH endocrinopathies. Medical management can lead to disease control in substantial number of cases and often entails use of multiple agents.

Pearls & Oy-sters: Sequential Bilateral Hearing and Vision Loss With Optic Disc Swelling Due to Sphenoid Bone Craniofacial Fibrous Dysplasia

Bilateral optic disc swelling is a common finding but rarely associated with multiple cranial neuropathies. In this case, an 18-year-old man presented with subacute sequential hearing loss followed by subacute sequential visual loss. Clinical examination revealed bilateral optic disc swelling. Lumbar puncture revealed a normal opening pressure of 15 cmH₂o. This case discusses a rare but important cause of bilateral optic disc swelling in the context of hearing loss, disequilibrium, and a normal CSF opening pressure. An overview of the literature is provided, and treatment options are discussed to guide further management of similar cases.

Case Report: A Neuro-Ophthalmological Assessment of Vision Loss in a Pediatric Case of McCune-Albright Syndrome

Patients diagnosed with McCune-Albright Syndrome (MAS) frequently manifest craniofacial fibrous dysplasia (FD). Craniofacial FD can impinge nerve fibers causing visual loss as well as craniofacial pain. Surgical decompression of affected nerves is performed, with variable efficacy, in an attempt to restore function or alleviate symptoms. Here, we present a case of a 12-year-old MAS patient with visual deficits, particularly in the left eye (confirmed by enlarged blind spots on Goldmann visual field testing), and craniofacial pain. Decompression surgery of the left optic nerve mildly improved vision, while persistent visual deficits were noted at a 3-month follow-up assessment. An in-depth, imaging-based evaluation of the visual system, including the retinal nerve fiber layer, optic nerves, and central nervous system (CNS) visual pathways, revealed multiple abnormalities throughout the visual processing stream. In the current FD/MAS patient, a loss of white matter fiber density within the left optic radiation and functional changes involving the left primary visual cortex were observed. Aberrant structural and functional abnormalities embedded within central visual pathways may play a role in facilitating deficits in vision in FD/MAS and contribute to the variable outcome following peripheral nerve decompression surgery.

Fibrous dysplasia: A rare cause of optic neuropathy

Fibrous dysplasia (FD) is a progressive and benign osteodystrophic disease where cranial bones are most commonly affected. In this case report, we present a 27-year-old patient with previous diagnosis of FD who was referred to our clinic with sudden loss of visual acuity and color discrimination. Examination of the right eye was normal, whereas visual acuity on the left eye was 6/9 and color vision (CV) with Ishihara test plates was 9/12. The visual field (VF) demonstrated a peripheral concentric defect on the left eye. As visual acuity in the left eye decreased to 6/30 and computed tomography imaging of the brain and orbit showed optic nerve compression by immature bony structures, optic nerve decompression was recommended with the diagnosis of compressive optic neuropathy. Endoscopic transnasal orbital and optic canal decompression was performed. At the postoperative course, visual acuity on the left eye turned to 6/6, CV was 12/12, and VF improved markedly. In subjects with craniofacial FD, a multidisciplinary approach is important. If there is evidence of compressive optic neuropathy, surgery should be performed.

[Early manifestation and progressive multicomponent current of McCune-Albright-Braitsev syndrome in a girl 9 years old: a clinical case and literature review]

McCune-Albright-Braitsev Syndrome (MAB syndrome) is a very rare multisystem disease manifested by fibrous bone dysplasia, coffee-and-milk colored spots, hyperfunction of various endocrine glands and a number of pathologies of other body systems. We present a description of a clinical case of a severe progressive course of MAB Syndrome in a nine-year-old girl. With this diagnosis, the girl is observation of the girl began when she was 2.5 years old, when spots of coffee-and-milk, polyosseous fibrous dysplasia, peripheral premature sexual development against a backdrop of estrogen--secreting ovarian cysts, multinodular goiter were detected. In the process of dynamic observation, it was noted that the child's active growth stopped against a backdrop of deformities of the skeletal system with multiple repeated fractures of the extremities; progression of skull deformity with stenosis of the optic nerve canals and deterioration of visual acuity; development of STH hypersecretion, hypophosphatemic rickets, tachycardia. Appropriate suppressive / replacement therapy was prescribed for each of the endocrine dysfunctions. The article presents algorithms for examining a girl in dynamics, criteria for choosing a component-wise management tactics and a discussion of the features of the course of all manifestations of the Syndrome.

Long-Term Clinical Course of Benign Fibro-Osseous Lesions in the Paranasal Sinuses

Objectives

Fibro-osseous lesions of the paranasal sinuses can present various clinical manifestations. This study aimed to report the long-term clinical course of benign fibro-osseous lesions (BFOLs) in the paranasal sinuses, including clinical and radiologic features.

Methods

Radiologically confirmed BFOLs between 1994 and 2016, with the exclusion of osteoma cases, were retrospectively reviewed. We compared demographic characteristics between the surgery and observation groups. The reasons for the imaging study, radiographic features, histopathology, and clinical course based on serial image scans were analyzed.

Results

In total, 183 subjects were selected from a thorough review of head and neck radiologic tests (n=606,068) at a tertiary referral hospital over 22 years. Patients’ mean age was 28.6±18.1 years, and 56.3% were males. A diagnostic imaging workup was performed in 55.7% of patients due to facial asymmetry, headache, skull mass, or other symptoms related to BFOLs. In other patients (37.7%), BFOLs were found incidentally on computed tomography or magnetic resonance imaging. The most common diagnosis was fibrous dysplasia, followed by ossifying fibroma, based on both radiologic exams and histopathologic results. In total, 42.6% of the patients underwent surgery because of subjective symptoms or esthetic concerns. The patients who underwent surgery were younger (P<0.001) and had a longer follow-up duration (P<0.001) than those who underwent observation. Patients who experienced lesion growth (11.5%) were younger (P<0.001) and had more lesion sites (P=0.018) than those who did not, regardless of surgical treatment. Five patients underwent optic nerve decompression, and one patient experienced malignant transformation.

Conclusion

BFOL in the paranasal sinuses is a rare disease, and most cases were observed without specific treatment. Surgical treatment should be considered in symptomatic patients with aggressive clinical features. Regular observation and management are needed, particularly in younger patients in their teens.

Best practice management guidelines for fibrous dysplasia/McCune-Albright syndrome: a consensus statement from the FD/MAS international consortium

Fibrous Dysplasia / McCune Albright syndrome (FD/MAS) represents a wide spectrum of diseases due to somatic gain-of-function mutations of the GNAS gene. The mutation leads to overactivity in the target tissues and to a wide phenotype of clinical features that vary in severity and age of onset. The rarity of the disease and its variable presentation to multiple specialities often leads to misdiagnosis and inappropriate variability in investigations and treatments. To address this, our international consortium of clinicians, researchers, and patients’ advocates has developed pragmatic clinical guidelines for best clinical practice for the definition, diagnosis, staging, treatment and monitoring for FD/MAS to empower patients and support clinical teams in both general and specialised healthcare settings. With the lack of strong evidence to inform care, the guidelines were developed based on review of published literature, long-standing extensive experience of authors, input from other healthcare professionals involved in the care of FD/MAS patients and feedback from patients and patient groups across the globe. This has led to the formulation of a set of statements to inform healthcare professionals, patients, their families, carers and patient groups of the best practice of care. It is anticipated the implementation of these recommendations will lead to improvement in the care of patients with FD/MAS internationally.

Cystic Degeneration of Craniofacial Fibrous Dysplasia

BACKGROUND

Fibrous dysplasia (FD) is most often a slowly progressive benign disease in which the normal bone structure is replaced by fibrous and osteoid tissue.

CASE DESCRIPTION

A 16-year-old adolescent, known with FD in the sphenoid bone, suffered an acute decreased visual acuity with papilledema on the left eye. The radiologic images were best compatible with cystic degeneration of the known FD with optic nerve compression in the optic canal. Decompression of the optic nerve was performed through an endoscopic exploration of the left sphenoid sinus. The visual acuity recovered completely.

CONCLUSIONS

In FD with cystic changes, leading to acute signs of optic nerve compression, early aggressive surgical decompression is strongly recommended. Cystic degeneration of the FD, although rare, should be considered.

Growth hormone-Insulin-like growth factor 1 axis hyperactivity on bone fibrous dysplasia in McCune-Albright Syndrome

CONTEXT

In fibrous dysplasia (BFD), normal bone and bone marrow are replaced by fibro-osseous tissue, leading to fracture, deformity and pain. BFD may be isolated, or in association with cutaneous hyperpigmentation and/or hyperfunctioning endocrinopathies, termed McCune-Albright syndrome (MAS). GH hypersecretion has been described in 10%-20% of MAS-BFD patients. Aim of the study was to determine the impact of GH-insulin like growth factor 1 (IGF1) axis hyperactivity on MAS-BFD morbidities and the efficacy of GH excess therapy.

DESIGN AND PATIENTS

A multicentric cross-sectional analysis was conducted on three different MAS cohorts. From 195 MAS patients, 37 subjects (19%) with GH excess were identified and compared with 34 MAS controls without GH hypersecretion.

RESULTS

Mean head circumference SDS was significantly higher in GH excess: 4.025 SDS vs 0.683 SDS (P < .0001). The risk of optic neuropathy (Odds ratio 4.231; P = .039), hearing deficit (Odds ratio 2.961; P = .0481), facial asymmetry (Odds ratio 6.563; P = .0192), malignancies (Odds ratio 15.24; P = .0173) were higher in GH excess group. Overall, pharmacotherapy (octreotide alone 10-30 mg/mo or with pegvisomant 10-20 mg/d) was effective in IGF1 normalization (IGF1 Z-score between -2 and +2 SDS) in 21/29 patients (72.4%) with good compliance to the regimen. Late diagnosis and GH excess treatment after 16 years old of age was associated with an increased risk of optic neuropathy (Odds ratio 4.500; P = .0491) and growth of pituitary adenomas (Odds ratio 7.846; P = .050).

CONCLUSIONS

GH-IGF1 hyperactivity increases risk of morbidities in MAS. Medical therapy is effective in normalizing IGF1 in most patients, and early treatment during paediatric age is associated with a decreased risk of optic neuropathy and GH-secreting adenomas growth.

Fibrous dysplasia imitating malignancy

Fibrous dysplasia is a benign bone disease, presenting as monostotic or polyostotic lesions, or as part of a syndrome (McCune-Albright/Mazabraud). Its clinical course shows a variegated picture and the progression of its growth is unpredictable. In the workup of 39 fibrous dysplasia cases in the cranio-facial area, four cases presented fast growth tendencies, of which two patients with McCune-Albright syndrome showed malignant-like rapid growth. This local aggressive form is extremely rare, and the concept of this issue has not been clearly defined. With regard to the speed of growth a volumetric-time analysis in one of our cases demonstrated a 74 days tumor doubling rate with an exponential growth curve. According to the literature the aggressive form presented extra-cranially mainly at an adult age, whereas its appearance in our cranio-facial patient collective was much younger. Distinguishing nonmalignant and malignant aggressive forms is difficult and highly inconsistent in the literature. We therefore implemented a quantitative growth measure analysis to define aggressive forms based on progression and speed of growth and impartial of type of FD, localization or functional incapacity. Due to our study findings and literature review we state a prevalence of an aggressive form might be possibly about 5 %.

Optical Coherence Tomography in the Management of Skull Base Fibrous Dysplasia with Optic Nerve Involvement

BACKGROUND

Fibrous dysplasia (FD) of the skull base can manifest with optic nerve compression. As most patients initially do not experience vision loss, controversy exists whether to proceed with prophylactic surgical decompression or elect for conservative observation. Optical coherence tomography (OCT), a physiologic imaging modality widely used to assess the condition of the retinal nerve fiber layer (RNFL), has been useful in monitoring compressive tumors on the optic nerve. This study evaluated potential use of OCT in management of patients with fibrous dysplasia and optic nerve involvement.

METHODS

Six patients with suspected optic nerve compression who underwent OCT imaging as part of a neuro-ophthalmic examination were reviewed over a 2-year period. Patient records were evaluated for visual examination measures, most notably the presence of optic neuropathy, and radiographic measures on computed tomography. Measures were compared by age-adjusted RNFL thickness (above or below fifth percentile) on OCT imaging.

RESULTS

Two patients were found to have mild optic neuropathy in 1 eye each. Three of 12 eyes fell below the age-adjusted fifth percentile of RNFL thickness. Presence of optic neuropathy was associated with abnormal age-adjusted RNFL thickness but not with optic nerve compression (P = 0.45).

CONCLUSIONS

Abnormal RNFL thickness as measured by OCT better predicted the presence of optic neuropathy than computed tomography alone. OCT may be a valuable imaging modality to monitor patients with fibrous dysplasia for development of optic neuropathy during periods of conservative watchful waiting.

Natural history of cranial fibrous dysplasia revealed during long-term follow-up: Case report and literature review

BACKGROUND

Fibrous dysplasia (FD) is a rare developmental disease characterized by the replacement of bone marrow with proliferating fibro-osseous tissue. There exist three forms of FD-monostotic, polyostotic, and that associated with McCune-Albright syndrome. The disease can present in different locations and with a variety of symptoms. One of the more common locations of FD occurrence is the craniofacial region. Treatment of asymptomatic FD often involves conservative management with serial imaging. Medical management with bisphosphonates is an option, though long-term efficacy data are lacking. Surgical resection is usually reserved for very large or symptomatic lesions.

CASE DESCRIPTION

We discuss the most unusual case of a 52-year-old male found to have a left pterional mass while being worked up for sinus headaches. The patient elected to follow this lesion conservatively, and imaging several years later showed obvious growth which accelerated in the last 4 years during an 18-year observational period. He ultimately underwent successful resection of an extradural and intradural FD.

CONCLUSIONS

The significant growth potential of these lesions was revealed in this patient, in whom conservative management had been adopted. Despite optimal surgical resection and outcome in this case, the importance of surveillance imaging and perhaps earlier intervention cannot be underestimated when managing cranial FD.

Prognostic Factors From an Epidemiologic Evaluation of Fibrous Dysplasia of Bone in a Modern Cohort: The FRANCEDYS Study

Fibrous dysplasia of bone (FD) is a rare genetic but sporadic bone disease that can be responsible for bone pain, fracture, and bone deformity. The prognosis may be difficult to establish because of the wide spectrum of disease severity. We have analyzed the data from the French National Reference center for FD. We have established a database from standardized medical records. We have made descriptive statistics of the various forms of FD and examined the prognostic factors by multivariable logistic regression analysis, with a parsimonious stepwise method. The primary outcome was a clinically relevant composite index combining bone pain (visual analogic scale >3) and/or incident fracture. In our modern cohort of 372 patients, the median age at diagnosis was 23 years. The revealing symptom (at a median age of 18 years) was bone pain in 44% of patients and a fracture in 9%, but the diagnosis was fortuitous in 25% of cases. Monostotic forms represented 58% of patients and polyostotic forms 42%. The femur was the most commonly affected bone (44% of patients), followed by the skull (38%). Twelve percent of patients had McCune-Albright syndrome (MAS). With a median duration of follow-up of 7 years among 211 patients, we observed an incidence of fracture of 17% and 51% of patients had no bone pain at the end of follow-up (with or without bisphosphonate therapy). In univariate analysis, younger age at diagnosis, renal phosphate wasting, a polyostotic form, prevalent fracture, and bisphosphonate use were significant predictors. In the multivariate model, the polyostotic form and bisphosphonate use remained significant predictors. In conclusion, in a national referral center for FD, one patient on follow-up out of six had incident fracture. A polyostotic form was the main risk factor of a poorer outcome. © 2016 American Society for Bone and Mineral Research.

Endoscopic Endonasal Optic Nerve Decompression for Fibrous Dysplasia

Objective To evaluate visual outcomes and potential complications for optic nerve decompression using an endoscopic endonasal approach (EEA) for fibrous dysplasia. Design Retrospective chart review of patients with fibrous dysplasia causing extrinsic compression of the canalicular segment of the optic nerve that underwent an endoscopic endonasal optic nerve decompression at the University of Pittsburgh Medical Center from 2010 to 2013. Main Outcome Measures The primary outcome measure assessed was best-corrected visual acuity (BCVA) with secondary outcomes, including visual field testing, color vision, and complications associated with the intervention. Results A total of four patients and five optic nerves were decompressed via an EEA. All patients were symptomatic preoperatively and had objective findings compatible with compressive optic neuropathy: decreased visual acuity was noted preoperatively in three patients while the remaining patient demonstrated an afferent pupillary defect. BCVA improved in all patients postoperatively. No major complications were identified. Conclusion EEA for optic nerve decompression appears to be a safe and effective treatment for patients with compressive optic neuropathy secondary to fibrous dysplasia. Further studies are required to identify selection criteria for an open versus an endoscopic approach.

Acromegaly and McCune-Albright syndrome

BACKGROUND

McCune-Albright syndrome (MAS) includes the triad of poly/monostotic fibrous dysplasia, café-au-lait spots, and hyperfunctioning endocrinopathies. Acromegaly affects around 20% of MAS patients.

AIMS

The objective was to review all reported cases of acromegaly associated with MAS.

METHODS

All studies and case reports of acromegaly in patients with MAS were systematically sought in the world literature up to January 2013. We also included new data (from three unreported cases) and updated data on 23 previously reported patients from our two centers.

RESULTS

We reviewed the cases of 112 patients (65 males). Mean age at diagnosis of acromegaly was 24.4 years (range, 3-64). Among the 40 pediatric patients, 23 (57%) had precocious puberty. GH/IGF-1 excess was suggested by accelerated growth in 85% of pediatric cases. Acromegaly was almost always associated with skull base fibrous dysplasia. Modern imaging techniques (computed tomography or magnetic resonance imaging) revealed an adenoma in 54% of the patients (macroadenoma in more than two-thirds). Median GH levels and mean IGF-1 SD score at diagnosis were 57 μg/L (2.8 to 291 μg/L) and 8 (2.3 to 24), respectively. Hyperprolactinemia was present in 81% (mean, 149 μg/L; range, 21-600). Pituitary surgery, performed in 25 cases, very rarely cured the GH/IGF-1 excess. Somatostatin analogs improved GH/IGF-1 levels in most patients but achieved control of acromegaly in only 17 (30%) of 56 patients. Pegvisomant achieved normal IGF-1 levels in 10 of 13 cases.

CONCLUSION

Acromegaly, which is present in 20-30% of patients with MAS, raises particular diagnostic and therapeutic issues.

Disease severity and functional factors associated with walking performance in polyostotic fibrous dysplasia

The purpose of this study was to determine the association between measures of disease severity, impairment, and ambulation ability in persons with polyostotic fibrous dysplasia (PFD). A cross-sectional sample of 81 patients (ages 5-57) with polyostotic fibrous dysplasia was evaluated as part of an ongoing study. Subjects were scored on the Skeletal Disease Burden Score (SDBS), completed a 9-minute walk test (9MW), manual muscle testing (MMT), and measurements of range of motion (ROM). Correlations between continuous variables were calculated using the Pearson correlation coefficient and ordinal variables by Spearman correlation coefficient. It was found that subjects with more severe disease walked slower than those with less skeletal disease, with the exception of the youngest subjects. Walking velocity was faster in subjects with better hip strength and range of motion and slower in those with bilateral coxa vara. Those subjects with more severe disease had less range of motion, were weaker at the hips, and more likely to have leg length discrepancy. Skeletal disease severity was associated with hip weakness, leg length discrepancy, and loss of range of motion. In most cases, findings did not differ in the presence or absence of associated endocrinopathies. Skeletal disease severity, MMT and ROM each has an impact on walking efficiency in persons with PFD. These findings suggest that treatment focused on strategies to improve or, at least, maintain hip strength and range of motion, correct leg length discrepancies and hip malalignment may help preserve ambulation ability in persons with PFD and that treatment should begin at a young age.

Sinonasal disease in polyostotic fibrous dysplasia and McCune-Albright Syndrome

OBJECTIVES/HYPOTHESIS

To characterize the spectrum, symptoms, progression, and effects of endocrine dysfunction on sinonasal disease in polyostotic fibrous dysplasia (PFD) and McCune-Albright Syndrome (MAS).

STUDY DESIGN

Retrospective review.

METHODS

A prospectively followed cohort of subjects with PFD/MAS underwent a comprehensive evaluation that included otolaryngologic and endocrine evaluation, and imaging studies. Head and facial computed tomography scans were analyzed, and the degree of fibrous dysplasia (FD) was graded using a modified Lund-MacKay scale. Those followed for >4 years were analyzed for progression.

RESULTS

A total of 106 patients meeting inclusion criteria were identified with craniofacial FD. A majority (92%) demonstrated sinonasal involvement. There were significant positive correlations between the sinonasal FD scale score and chronic congestion, hyposmia, growth hormone excess, and hyperthyroidism (P < .05 for all). Significant correlations were not found for headache/facial pain or recurrent/chronic sinusitis. Thirty-one subjects met the criteria for longitudinal analysis (follow-up mean, 6.3 years; range, 4.4-9 years). Those who demonstrated disease progression were significantly younger than those who did not (mean age, 11 vs. 25 years). Progression after age of 13 years was uncommon (n = 3) and minimal. Concomitant endocrinopathy or bisphosphonate use did not have any significant effect on progression of disease.

CONCLUSIONS

Sinonasal involvement of fibrous dysplasia in PFD/MAS is common. Symptoms are usually few and mild, and disease progression occurs primarily in young subjects. Concomitant endocrinopathy is associated with disease severity, but not progression.

Optic neuropathy in McCune-Albright syndrome: effects of early diagnosis and treatment of growth hormone excess

CONTEXT

GH excess is a serious complication of McCune-Albright syndrome (MAS) and has been associated with craniofacial morbidity.

OBJECTIVE

The aim of the study was to determine whether early diagnosis and treatment of MAS-associated GH excess prevents optic neuropathy and hearing impairment, the major morbidities associated with GH excess.

DESIGN AND SETTING

A retrospective cross-sectional analysis was conducted at a clinical research center.

PATIENTS

Twenty-two subjects with MAS-associated GH excess and 21 control MAS subjects without GH excess were included in the study.

INTERVENTION

Biochemical testing included random GH, nadir GH after glucose load, nadir GH on frequent sampling, and IGF-I Z-score. Subjects underwent imaging, ophthalmological, audiological, and otolaryngological assessment. Treatment included octreotide, pegvisomant, transphenoidal surgery, and/or radiotherapy as indicated.

MAIN OUTCOME MEASURE

Association of optic neuropathy and hearing impairment to age at GH excess diagnosis/treatment was measured.

RESULTS

Of 129 MAS subjects, 26 (20%) were diagnosed with GH excess based on elevation of two measures of GH function. Of these, 22 subjects were candidates for pharmacological intervention. Optic neuropathy was significantly correlated with intervention status, with no cases in the early intervention group (diagnosed/treated before age 18) or the control group, and four of seven (57%) in the late intervention group (diagnosed/treated after age 18) (Fisher's exact test; odds ratio, 0.027; P = 0.0058). Early diagnosis/intervention was not associated with reduction in hearing deficits (odds ratio, 1.25; P = 1.00). Mean head circumference SD score was significantly higher in the late (6.08; range, 2.70 to 22.56) than the early intervention (2.67; range, -0.65 to 6.72) or control groups (2.13; range, -2.06 to 7.79) (P = 0.003).

CONCLUSIONS

Early diagnosis/treatment of GH excess in MAS is important to prevent optic neuropathy and craniofacial expansion. The relationship between hearing deficits and GH excess remains less clear and requires further study.

Somatic GNAS mutation causes widespread and diffuse pituitary disease in acromegalic patients with McCune-Albright syndrome

CONTEXT

McCune-Albright syndrome (MAS) is caused by sporadic mutations of the GNAS. Patients exhibit features of acromegaly. In most patients, GH-secreting pituitary adenomas have been held responsible for this presentation. However, surgical adenomectomy rarely eliminates excess GH production.

OBJECTIVE

The aim of this study was to elucidate pituitary pathology in patients with MAS and to explain the basis of failure of adenomectomy to eliminate GH hypersecretion.

DESIGN AND SETTING

We conducted a case series at the National Institutes of Health.

INTERVENTION(S)

Interventions included medical therapy and transsphenoidal surgery.

PATIENTS AND MAIN OUTCOME MEASURES

We studied clinical and imaging features and the histology and molecular features of the pituitary of four acromegalic MAS patients.

RESULTS

We identified widespread and diffuse pituitary gland disease. The primary pathological changes were characterized by hyperplastic and neoplastic change, associated with overrepresentation of somatotroph cells in structurally intact tissue areas. Genetic analysis of multiple microdissected samples of any type of histological area consistently revealed identical GNAS mutations in individual patients. The only patient with remission after surgery received complete hypophysectomy in addition to removal of multiple GH-secreting tumors.

CONCLUSIONS

These findings indicate developmental effects of GNAS mutation on the entire anterior pituitary gland. The pituitary of individual cases contains a spectrum of changes with regions of normal appearing gland, hyperplasia, and areas of fully developed adenoma formation, as well as transitional stages between these entities. The primary change underlying acromegaly in MAS patients is somatotroph hyperplasia involving the entire pituitary gland, with or without development of somatotroph adenoma. Thus, successful clinical management, whether it is medical, surgical, or via irradiation, must target the entire pituitary, not just the adenomas evident on imaging.

Clinical guidelines for the management of craniofacial fibrous dysplasia

Fibrous dysplasia (FD) is a non-malignant condition caused by post-zygotic, activating mutations of the GNAS gene that results in inhibition of the differentiation and proliferation of bone-forming stromal cells and leads to the replacement of normal bone and marrow by fibrous tissue and woven bone. The phenotype is variable and may be isolated to a single skeletal site or multiple sites and sometimes is associated with extraskeletal manifestations in the skin and/or endocrine organs (McCune-Albright syndrome). The clinical behavior and progression of FD may also vary, thereby making the management of this condition difficult with few established clinical guidelines. This paper provides a clinically-focused comprehensive description of craniofacial FD, its natural progression, the components of the diagnostic evaluation and the multi-disciplinary management, and considerations for future research.

McCune-Albright syndrome and the extraskeletal manifestations of fibrous dysplasia

Fibrous dysplasia (FD) is sometimes accompanied by extraskeletal manifestations that can include any combination of café-au-lait macules, hyperfunctioning endocrinopathies, such as gonadotropin-independent precocious puberty, hyperthyroidism, growth hormone excess, FGF23-mediated renal phosphate wasting, and/or Cushing syndrome, as well as other less common features. The combination of any of these findings, with or without FD, is known as McCune-Albright syndrome (MAS). The broad spectrum of involved tissues and the unpredictable combination of findings owe to the fact that molecular defect is due to dominant activating mutations in the widely expressed signaling protein, Gsα, and the fact these mutations arises sporadically, often times early in development, prior to gastrulation, and can distribute across many or few tissues.The complexity can be mastered by a systematic screening of potentially involved tissues and cognizance that the pattern of involved tissues is established, to some degree, in utero. Thorough testing allows the clinician to establish, often times at presentation, the full extent of the disease, and importantly as well what tissues are unaffected. Treatment and follow-up can then be focused on affected systems and a meaningful prognosis can be offered to the patient and family. The authors outline screening and treatment strategies that allow for effective management of the extraskeletal manifestations of FD.

Surgery versus watchful waiting in patients with craniofacial fibrous dysplasia--a meta-analysis

Background

Fibrous dysplasia (FD) is a benign bone tumor which most commonly involves the craniofacial skeleton. The most devastating consequence of craniofacial FD (CFD) is loss of vision due to optic nerve compression (ONC). Radiological evidence of ONC is common, however the management of this condition is not well established. Our objective was to compare the long-term outcome of patients with optic nerve compression (ONC) due to craniofacial fibrous dysplasia (CFD) who either underwent surgery or were managed expectantly.

Methodology/Principal Findings

We performed a meta-analysis of 27 studies along with analysis of the records of a cohort of patients enrolled in National Institutes of Health (NIH) protocol 98-D-0145, entitled Screening and Natural History of Fibrous Dysplasia, with a diagnosis of CFD. The study group consisted of 241 patients; 122 were enrolled in the NIH study and 119 were extracted from cases published in the literature. The median follow-up period was 54 months (range, 6–228 months). A total of 368 optic nerves were investigated. All clinically impaired optic nerves (n = 86, 23.3%) underwent therapeutic decompression. Of the 282 clinically intact nerves, 41 (15%) were surgically decompressed and 241 (85%) were followed expectantly. Improvement in visual function was reported in fifty-eight (67.4%) of the clinically impaired nerves after surgery. In the intact nerves group, long-term stable vision was achieved in 31/45 (75.6%) of the operated nerves, compared to 229/241 (95.1%) of the non-operated ones (p = 0.0003). Surgery in asymptomatic patients was associated with visual deterioration (RR 4.89; 95% CI 2.26–10.59).

Conclusions

Most patients with CFD will remain asymptomatic during long-term follow-up. Expectant management is recommended in asymptomatic patients even in the presence of radiological evidence of ONC.

McCune-Albright syndrome

McCune-Albright syndrome (MAS) is classically defined by the clinical triad of fibrous dysplasia of bone (FD), café-au-lait skin spots, and precocious puberty (PP). It is a rare disease with estimated prevalence between 1/100,000 and 1/1,000,000. FD can involve a single or multiple skeletal sites and presents with a limp and/or pain, and, occasionally, a pathologic fracture. Scoliosis is common and may be progressive. In addition to PP (vaginal bleeding or spotting and development of breast tissue in girls, testicular and penile enlargement and precocious sexual behavior in boys), other hyperfunctioning endocrinopathies may be involved including hyperthyroidism, growth hormone excess, Cushing syndrome, and renal phosphate wasting. Café-au-lait spots usually appear in the neonatal period, but it is most often PP or FD that brings the child to medical attention. Renal involvement is seen in approximately 50% of the patients with MAS. The disease results from somatic mutations of the GNAS gene, specifically mutations in the cAMP regulating protein, G_s alpha. The extent of the disease is determined by the proliferation, migration and survival of the cell in which the mutation spontaneously occurs during embryonic development. Diagnosis of MAS is usually established on clinical grounds. Plain radiographs are often sufficient to make the diagnosis of FD and biopsy of FD lesions can confirm the diagnosis. The evaluation of patients with MAS should be guided by knowledge of the spectrum of tissues that may be involved, with specific testing for each. Genetic testing is possible, but is not routinely available. Genetic counseling, however, should be offered. Differential diagnoses include neurofibromatosis, osteofibrous dysplasia, non-ossifying fibromas, idiopathic central precocious puberty, and ovarian neoplasm. Treatment is dictated by the tissues affected, and the extent to which they are affected. Generally, some form of surgical intervention is recommended. Bisphosphonates are frequently used in the treatment of FD. Strengthening exercises are recommended to help maintaining the musculature around the FD bone and minimize the risk for fracture. Treatment of all endocrinopathies is required. Malignancies associated with MAS are distinctly rare occurrences. Malignant transformation of FD lesions occurs in probably less than 1% of the cases of MAS.

Current approach to fibrous dysplasia of bone and McCune-Albright syndrome

Fibrous dysplasia (FD) of bone is an uncommon disease caused by sporadic, congenital mutations in the cAMP regulating protein, G(s)alpha. It is an example of somatic mosaicism in which a wide spectrum of disease is possible. Widespread skeletal involvement is often associated with varying combinations of café-au-lait skin spots, and/or endocrine dysfunction (precocious puberty, renal phosphate wasting, hyperthyroidism, and/or growth hormone excess). Unrecognized and untreated endocrine dysfunction can exacerbate the skeletal disease. The diagnosis is usually established on clinical grounds on the basis of physical examination and typical radiographic appearance. Occasionally, gene testing of affected tissue may be helpful. The skeletal sites involved with disease are established at an early age, and the complications of fracture deformity are most pronounced in childhood. Bone pain in the absence of a fracture is more common in adults, but can also be present in children. Treatment with bisphosphonates is usually effective at relieving pain, but probably has no effect on the natural history of the disease. Scoliosis, which was previously thought to be an uncommon occurrence, has been shown to be common and progressive, and as such, warrants investigation and, when necessary, surgical treatment. The surgical management of FD remains challenging. Timing and technique remain controversial, but some consensus exists in that grafting materials (of any type) usually fail and should not be a central aspect of the surgical approach. Intramedullary devices are in general superior to side plates and screws. In extremely widespread disease with very early fracture and deformity, no surgical approach will affect final functional outcome. Efforts should be made for the initiation of international collaborative studies to better define optimal surgical approaches to the treatment of this challenging disease.