Fibrocartilaginous Dysplasia of the Proximal Femur in Two Pediatric Patients, Including a Pathologic Fracture in a Patient With McCune-Albright Syndrome.

Fibrocartilaginous dysplasia (FCD) is a variant of fibrous dysplasia that often involves the proximal femur in young adults. It has a similar appearance on imaging as other entities but has stippled calcifications within the lesion. The differential diagnosis often includes benign and malignant tumors such as fibrous dysplasia, chondroblastoma, enchondroma, and chondrosarcoma. Histology is required for diagnosis and treatment is typically surgical due to the potential for pain, pathologic fracture, and deformity. We report the clinical presentation, imaging findings, and management of two pediatric patients with fibrocartilaginous dysplasia of the proximal femur to (1) highlight that recognition that fibrous dysplasia may contain cartilage upon frozen section will avoid overly aggressive therapy, and (2) FCD can occur in the McCune-Albright syndrome.

Heterozygous gain of function variant in GUCY1A2 may cause autonomous ovarian hyperfunction.

PURPOSE: The purpose of this study was to characterize the phenotype associated with a de novo gain-of-function variant in the GUCY1A2 gene. METHODS: An individual carrying the de novo heterozygous variant c.1458G>T p.(E486D) in GUCY1A2 was identified by exome sequencing. The effect of the corresponding enzyme variant α2E486D/ß1 was evaluated using concentration-response measurements with wild-type enzyme and the variant in cytosolic fractions of HEK293 cells, UV-vis absorbance spectra of the corresponding purified enzymes, and examination of overexpressed fluorescent protein-tagged constructs by confocal laser scanning microscopy. RESULTS: The patient presented with precocious peripheral puberty resembling the autonomous ovarian puberty seen in McCune-Albright syndrome. Additionally, the patient displayed severe intellectual disability. In vitro activity assays revealed an increased nitric oxide affinity for the mutant enzyme. The response to carbon monoxide was unchanged, while thermostability was decreased compared to wild type. Heme content, susceptibility to oxidation, and subcellular localization upon overexpression were unchanged. CONCLUSION: Our data define a syndromic autonomous ovarian puberty likely due to the activating allele p.(E486D) in GUCY1A2 leading to an increase in cGMP. The overlap with the ovarian symptoms of McCune-Albright syndrome suggests an impact of this cGMP increase on the cAMP pathway in the ovary. Additional cases will be needed to ensure a causal link.

Recent research advances in pain mechanisms in McCune-Albright syndrome thinking about the pain mechanism of FD/MAS.

BACKGROUND: The lack of effective understanding of the pain mechanism of McCune-Albright syndrome (MAS) has made the treatment of pain in this disease a difficult clinical challenge, and new therapeutic targets are urgently needed to address this dilemma. OBJECTIVE: This paper summarizes the novel mechanisms, targets, and treatments that may produce pain in MAS and fibrous dysplasia (polyfibrous dysplasia, or FD). METHODS: We conducted a systematic search in the PubMed database, Web of Science, China Knowledge Network (CNKI) with the following keywords: "McCune-Albright syndrome (MAS); polyfibrous dysplasia (FD); bone pain; bone remodeling; G protein coupled receptors; GDNF family receptors; purinergic receptors and glycogen synthase kinase", as well as other keywords were systematically searched. Papers published between January 2018 and May 2023 were selected for finding. Initial screening was performed by reading the titles and abstracts, and available literature was screened against the inclusion and exclusion criteria. RESULTS: In this review, we systematically analyzed the cutting-edge advances in this disease, synthesized the findings, and discussed the differences. With regard to the complete mechanistic understanding of the pain condition in FD/MAS, in particular, we collated new findings on new pathways, neurotrophic factor receptors, purinergic receptors, interferon-stimulating factors, potassium channels, protein kinases, and corresponding hormonal modulation and their respective strengths and weaknesses. CONCLUSION: This paper focuses on basic research to explore FD/MAS pain mechanisms. New nonneuronal and molecular mechanisms, mechanically loaded responsive neurons, and new targets for potential clinical interventions are future research directions, and a large number of animal experiments, tissue engineering techniques, and clinical trials are still needed to verify the effectiveness of the targets in the future.

[Research progress on the pathogenic mechanisms, diagnosis and treatment of McCune-Albright syndrome].

McCune-Albright syndrome is a rare chimeric disorder due to mutations in the postzygotic GNAS gene. It belongs to the group of guanine nucleotide-binding protein diseases, affecting a wide range of individuals. It is characterized by fibrous dysplasia, café-au-lait skin macules, and precocious puberty with other variable clinical manifestations. At present, there are difficulties in the molecular diagnosis of McCune-Albright syndrome, and there is a lack of effective clinical treatments to halt or reverse the course and regression of the disease. This article summarizes the clinical manifestations, diagnosis, pathogenic molecular mechanisms, treatment and relevant fertility guidelines of McCune-Albright syndrome, with a view to further research and therapy of McCune-Albright syndrome.

Diagnostic journey for individuals with fibrous dysplasia / McCune albright syndrome (FD/MAS).

BACKGROUND: Reducing delayed diagnosis is a significant healthcare priority for individuals with rare diseases. Fibrous Dysplasia/ McCune Albright Syndrome (FD/MAS) is a rare bone disease caused by somatic activation mutations of NASA. FD/MAS has a broad clinical phenotype reflecting variable involvement of bone, endocrine and other tissues, distribution and severity. The variable phenotype is likely to prolong the diagnostic journey for patients further. AIM: To describe the time from symptom onset to final diagnosis in individuals living with FDMAS. METHODS: We used the UK-based RUDY research database ( www.rudystudy.org ), where patients self-report their diagnosis of FD/MAS. Participants are invited to complete the diagnostic journey based on the EPIRARE criteria. RESULTS: 51 individuals diagnosed with FD/MAS were included in this analysis. Among them, 70% were female, and the median age was 51.0 years (IQR 34.5-57.5]. 12 (35%) individuals reported McCune Albright Syndrome, 11 (21.6%) craniofacial and 11(21.6%) for each of poly- and mono-ostotic FD and 6 (11.8%) did not know their type of FD/MAS. Pain was the commonest first symptom (58.8%), and 47.1% received another diagnosis before the diagnosis of FD/MAS. The median time to final diagnosis from the first symptom was two years with a wide IQR (1,18) and range (0-59 years). Only 12 (23.5%) of individuals were diagnosed within 12 months of their first symptoms. The type of FD/MAS was not associated with the reported time to diagnosis. Significant independent predictors of longer time to final diagnosis included older current age, younger age at first symptom and diagnosis after 2010. CONCLUSION: Individuals with FDMAS have a variable time to diagnosis that can span decades. This study highlights the need for further research on how to improve diagnostic pathways within Orthopaedic and Ear, Nose and Throat (ENT)/Maxillofacial services. Our data provides a baseline to assess the impact of novel NHS diagnostic networks on reducing the diagnostic odyssey.

Choosing the Best Tissue and Technique to Detect Mosaicism in Fibrous Dysplasia/McCune-Albright Syndrome (FD/MAS).

GNAS-activating somatic mutations give rise to Fibrous Dysplasia/McCune-Albright syndrome (FD/MAS). The low specificity of extra-skeletal signs of MAS and the mosaic status of the mutations generate some difficulties for a proper diagnosis. We studied the clinical and molecular statuses of 40 patients referred with a clinical suspicion of FD/MAS to provide some clues. GNAS was sequenced using both Sanger and Next-Generation Sequencing (NGS). We were able to identify the pathogenic variants in 25% of the patients. Most of them were identified in the affected tissue, but not in blood. Additionally, NGS demonstrated the ability to detect more patients with mosaicism (8/34) than Sanger sequencing (4/39). Even if in some cases, the clinical information was not complete, we confirmed that, as in previous works, when the patients were young children with a single manifestation, such as hyperpigmented skin macules or precocious puberty, the molecular diagnosis was usually negative. In conclusion, as FD/MAS is caused by mosaic variants, it is essential to use sensitive techniques that allow for the detection of low percentages and to choose the right tissue to study. When not possible, and due to the low positive genetic rate, patients with FD/MAS should only be genetically tested when the clinical diagnosis is really uncertain.

[McCune-Albright syndrome: a case report and literature review]. / Syndrome de McCune-Albright : à propos d'un cas et revue de la littérature.

McCune-Albright syndrome is an inherited disease characterized by the association of fibrous dystrophy of bone, café-au-lait skin spots and precocious puberty revealing endocrine hyperactivity. Genetically, this disease is due to a mutation of the Gs protein responsible for activation of adenylate cyclase with excessive production of cAMP. The particular morphology of café-au-lait spots should suggest early diagnosis. Its treatment depends on the endocrinopathy from which the patient suffers and the extent of the fibrous dysplasia. Bisphosphonates have proven their effectiveness on bone pain and the limitation of fibrous dysplasia. Surgery retains its place in complicated forms. We report a rare case of McCune-Albright syndrome complicated by a femur fracture in a 12-year-old girl and we discuss the clinical and paraclinical characteristics of this pathological entity.

[The enigma of Henry IV's disease: Did he suffer from McCune-Albright syndrome/fibrous dysplasia?] / El enigma de la enfermedad de Enrique IV, rey de Castilla: ¿padeció síndrome de McCune-Albright/displasia fibrosa?

BACKGROUND: Henry IV King of Castile, last king of the Trastámara dynasty, was the brother of Isabella the Catholic. He is known as "the impotent". Based on previous descriptions by historians and biographers, Gregorio Marañón in 1922 described him as "eunuchoid dysplastic with acromegalic reaction and clear schizoid features". METHODS: In 1946, a post-mortem inspection was carried out on the mummified corpse found in the Monastery of Guadalupe. A written document and some photographs were recorded. We have collected the signs and symptoms described and applied the international classification of diseases recommended by the World Health Organisation, ICD11-2023. We have relied on the coins issued in the money of Henry IV, on which we have identified enlargement of the thyroid gland. RESULTS: With the data available at this time, we suggest that Henry IV most probably suffered from: facial and polyostotic bone dysplasia, kyphosis, limb limping, multiple endocrine disorders, acromegaly with macrognatia, nodular thyroid disease, malodorous diaphoresis, erectile dysfunction, hypospadias, abnormal sexual development, "feminoid pelvis", abdominal colic, oligodontia and dental displacement. It is possible that he also suffered from: precocious puberty, renal lithiasis with debilitating phosphaturia, carpal tunnel, thrombopenia and growth hormone-producing pituitary hyperplasia or adenoma. CONCLUSION: We suggest that Henry IV may have suffered from McCune-Albrigth syndrome associated with fibrous dysplasia, a rare disease due to gain-of-function mutations in the GNAS gene.

Value of rare diseases reference centers: impact on diagnosis and access to specialized care in fibrous dysplasia of bone.

INTRODUCTION: Reference Centers and Rare Disease Health Networks aim to improve the management of patients with rare diseases. The French reference center for Fibrous Dysplasia was certified in 2006. OBJECTIVE: The objective of our study was to assess the effectiveness of our reference center since its constitution. METHODS: In a retrospective cohort study, we compared the activity of our center, including the time elapsed between access to the center and the diagnostic delay of patients with Fibrous Dysplasia between two periods, 1994-2006 (before certification) and 2007-2019 (after certification). Data were extracted from patients' records (Easily®). Wilcoxon and Fisher tests were performed, using R®. RESULTS: Our cohort included 527 patients with Fibrous Dysplasia/Mc Cune Albright syndrome. The activity of the Fibrous Dysplasia center increased from 139 patients in the first period (1994-2006) to an additional 388 patients for the second period (2007-2019). Mean time elapsed to diagnosis of Fibrous Dysplasia was 1.5 years before 2007 and 1.9 years after 2007 (p = 0.12). Diagnosis was made before referral in over 80% of patients. There was a non-significant decrease in the number of patients with delayed diagnosis: 37 patients (44%) in the first period had a diagnostic delay and 94 patients (33%) in the second period (p = 0.07). Patients were referred to our center on average 6.8 years (before 2007) and 7.9 years (after 2007) after their diagnosis (p = 0.77). CONCLUSION: Healthcare organization with reference centers significantly impacted the management of patients with Fibrous Dysplasia/Mc Cune Albright syndrome, with a substantial increase in the activity of our center, that roughly tripled since certification. This healthcare organization was also associated with a trend toward decreasing diagnostic delay. However, diagnostic delay affected more than a third of patients and the time to access to the center remained extended (≈7-8 years after diagnosis). The current challenge lies in informing primary care providers and patients about education to rare diseases and existence of reference centers for earlier and more effective specialized management.

Case Report: Severe McCune-Albright syndrome presenting with neonatal Cushing syndrome: navigating through clinical obstacles.

Background: Café-au-lait skin macules, Cushing syndrome (CS), hyperthyroidism, and liver and cardiac dysfunction are presenting features of neonatal McCune-Albright syndrome (MAS), CS being the rarest endocrine feature. Although spontaneous resolution of hypercortisolism has been reported, outcome is usually unfavorable. While a unified approach to diagnosis, treatment, and follow-up is lacking, herein successful treatment and long-term follow-up of a rare case is presented. Clinical case: An 11-day-old girl born small for gestational age presented with deterioration of well-being and weight loss. Large hyperpigmented macules on the trunk, hypertension, hyponatremia, hyperglycemia, and elevated liver enzymes were noted. ACTH-independent CS due to MAS was diagnosed. Although metyrapone (300 mg/m2/day) was started on the 25th day, complete remission could not be achieved despite increasing the dose up to 1,850 mg/m2/day. At 9 months, right total and left three-quarters adrenalectomy was performed. Cortisol decreased substantially, ACTH remained suppressed, rapid tapering of hydrocortisone to physiological dose was not tolerated, and supraphysiological doses were required for 2 months. GNAS analysis from the adrenal tissue showed a pathogenic heterozygous mutation. During 34 months of follow-up, in addition to CS due to MAS, fibrous dysplasia, hypophosphatemic rickets, and peripheral precocious puberty were detected. She is still regularly screened for other endocrinopathies. Conclusion: Neonatal CS due to MAS is extremely rare. Although there is no specific guideline for diagnosis, treatment, or follow-up, addressing side effects and identifying treatment outcomes will improve quality of life and survival.

McCune-Albright Syndrome: A Case Report and Review of Literature.

McCune-Albright syndrome (MAS) is a rare sporadic condition defined by the classic triad of fibrous dysplasia of bone, café au lait skin macules, and hyperfunctioning endocrinopathies. The molecular basis of MAS has been ascribed to the post-zygotic somatic gain-of-function mutations in the GNAS gene, which encodes the alpha subunit of G proteins, leading to constitutive activation of several G Protein-Coupled Receptors (GPCRs). The co-occurrence of two of the above-mentioned cardinal clinical manifestations sets the diagnosis at the clinical level. In this case report, we describe a 27-month-old girl who presented with gonadotropin-independent precocious puberty secondary to an estrogen-secreting ovarian cyst, a café au lait skin macule and growth hormone, and prolactin excess, and we provide an updated review of the scientific literature on the clinical features, diagnostic work-up, and therapeutic management of MAS.

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.

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.

Severe craniofacial fibrous dysplasia associated with decreased visual acuity: a case report.

Fibrous dysplasia is a developmental abnormality characterized by the replacement of normal bone tissue by fibrous connective tissue with poorly organized bone trabeculae. This disorder rarely occurs in the craniofacial region, but in such cases it causes facial asymmetries and has severe clinical implications for the patient. This case report describes the treatment of an 18-year-old man who presented with complaints of facial deformity and decreased visual acuity. Cone beam computed tomography revealed a diffuse bone lesion affecting the region of the maxillary, frontal, and nasal bones on the left side of the face. After microscopic examination, the diagnosis of craniofacial fibrous dysplasia was made. The patient underwent a bilateral temporal craniotomy to perform decompression of the orbital apices and correct the loss of visual acuity. In addition, surgical cosmetic contouring of the facial bones was performed. The patient has been followed up by a multidisciplinary team; at his most recent examination, 18 months after the last surgical intervention, his clinical condition remained stable.

[OPTIC DISC EDEMA IN McCUNE-ALBRIGHT SYNDROME].

INTRODUCTION: Craniofacial polyostotic fibrous dysplasia, as part of McCune-Albright syndrome, can have severe complications including vision loss. Also, patients with this syndrome are at greater risk of secondary intra-cranial pressure elevation due to medication side effects. BACKGROUND: : A 6-year-old girl with McCune-Albright syndrome and polyostotic craniofacial fibrous dysplasia and optic canal narrowing, developed signs of slowly progressive optic nerve compression on clinical examination including deteriorating visual acuity, positive relative afferent pupillary defect )RAPD) and bilateral optic disc swelling. Imaging using optical coherence tomography (OCT) revealed progressive retinal nerve fiber layer thickening. Prior to deterioration, the dose of triptorelin, a gonadotrophin-releasing hormone analogue, she was treated with for precocious puberty, was increased. Medication cessation was followed by improvement in clinical and imaging findings. CONCLUSIONS: : McCune-Albright syndrome patients with craniofacial involvement and/or gonadotrophin-releasing hormone analogue treatment should be monitored regularly for clinical signs of optic neuropathy together with routine OCT imaging.

Cushing syndrome as a failed cardiac screen in a patient with McCune-Albright syndrome: a case report.

BACKGROUND: McCune-Albright syndrome is a complex disorder encompassing multiple endocrinopathies. These manifestations are secondary to a mutation in the stimulatory G-protein alpha subunit. Cushing syndrome is due to autonomous secretory function of the adrenal gland and is present in 7.1% of patients with McCune-Albright syndrome. Cardiac newborn screenings assist in the identification of critical congenital heart disease. These screenings have become part of routine postnatal care nationwide. CASE REPORT: A 6-week-old Caucasian male presented to a cardiologist at the University of Tennessee Health Science Center with left ventricular hypertrophy and poor feeding after a failed cardiac newborn screen. He had been previously seen at 2 weeks by a cardiologist on follow-up for abnormal critical congenital heart disease screening. Electrocardiogram and echocardiographic studies identified hypertrophic cardiomyopathy. Other examination findings revealed multiple characteristic café-au-lait lesions along with hypotonia and rounded facies. Given his cardiac disease, he was admitted to the hospital, where an evaluation was done for Cushing syndrome, showing elevated cortisol by immunoassay of 38 µg/dL (1.7-14.0 µg/dL, Vitros 5600) after a dexamethasone suppression test and urinary cortisol elevated to 35 µg/dL/24 hours (reference range 3-9 µg/dL/24 hours) (Esoterix; Calabasas, CA). He was started on metyrapone therapy to block synthesis of cortisol. His cortisol improved and was suppressed less than 2 µg/dL. His hypertension and clinical features of Cushing syndrome improved. CONCLUSIONS: This case demonstrates a unique presentation of Cushing syndrome in a young infant. This is the first case to our knowledge showing significant left ventricular hypertrophy resulting from Cushing syndrome identified following a failure on a critical congenital heart disease screen. It highlights the importance of considering of McCune-Albright syndrome in patients with Cushing syndrome, especially if other clinical features are present. Medical therapy can be used to treat Cushing syndrome and can result in improvement in the cardiovascular pathology.

Malignant Sarcomatous Degeneration of Craniofacial Fibrous Dysplasia.

BACKGROUND: Fibrous dysplasia (FD) is an uncommon bone disease characterized by the replacement of normal bone architecture with abnormal fibro-osseous connective tissue. Here, we discuss 2 cases of craniofacial FD, with malignant sarcomatous degeneration - a rare and morbid complication of the disease. CASE HISTORY: Two cases of craniofacial FD with malignant degeneration are presented. In the first, a 68-year-old male with a history of FD presented with acutely worsening left-sided facial pain and V2 and V3 hypoesthesia. Imaging findings suggested a large infratemporal fossa mass with biopsy demonstrating sarcomatous degeneration. Radical craniofacial resection achieved a gross total resection with likely microscopic disease. The patient was unable to tolerate adjuvant chemotherapy or radiation and succumbed to his disease 13 months following surgery.In the second case, a 36-year-old male with McCune-Albright Syndrome and craniofacial FD presented with acutely worsening left-sided headaches and midface hypoesthesia. Imaging revealed a heterogenous and expansile lesion with erosive changes in the left nasal cavity and infratemporal fossa. Pathology was suggestive of low grade sarcomatous degeneration. Given the extensive involvement of the skull base, the tumor was deemed unresectable, and the patient soon died following initiation of chemotherapy. CLINICAL RELEVANCE: Malignant sarcomatous transformation is a rare and challenging complication of craniofacial FD. Indolent onset, advanced spread at time of presentation, and close relationship with vital neurovascular structures are all hurdles for the treating clinician. The entity poses a diagnostic dilemma, as pathological analysis can be equivocal and may mimic nonmalignant processes, such as locally aggressive FD.

McCune-Albright Syndrome in Infant with Growth Hormone Excess.

BACKGROUND: McCune-Albright is a rare syndrome, caused by mutation of the GNAS1 gene, and is characterized by an appearance of multiple endocrinopathies, most commonly premature puberty, polyostotic fibrous dysplasia and skin changes called cafe au lait macules. CASE REPORT: We present the case of a patient who is, to the best of our knowledge and after extensive review of literature, the youngest McCune-Albright syndrome patient with growth hormone excess, diagnosed at 8.9 months of age. An extensive diagnostic procedure was done upon the diagnosis. Hormonal assessment was performed and all hormone levels were within reference range, and an additional oral glucose suppression that noted the presence of growth hormone excess. Magnetic resonance imaging of the pituitary gland did not detect a tumor process. The genetic analysis of the GNAS1 gene from skin punch biopsy came back negative. Octreotide was administered as therapy for growth hormone excess at 9.8 months. After the introduction of therapy, we noted a decrease in growth rate from 29.38 to 16.6 cm/year. CONCLUSION: This case report emphasizes the lack of available data on treatment of growth hormone excess and follow-up in pediatric population and the need for further research.