CT and MR Imaging in a Large Series of Patients with Craniofacial Fibrous Dysplasia

Dissecting the heterogeneity of craniofacial lesions in patients with fibrous dysplasia/McCune-Albright Syndrome

Fibrous dysplasia/McCune-Albright Syndrome (FD/MAS) frequently involves the craniofacial skeleton. Craniofacial fibrous dysplasia lesions exhibit diverse imaging characteristics on multimodality evaluation, utilizing radiographs, computed tomography (CT), magnetic resonance imaging (MRI), and 18F-sodium fluoride positron emission tomography (18F-NaF PET). A multimodal imaging classification of craniofacial fibrous dysplasia lesions may offer clinical insights into the types of lesions that are (1) prone to progression, (2) amenable to intervention (i.e., pharmacological or surgical), or (3) associated with symptoms such as pain. In this prospective, preliminary single site study of 15 patients with FD/MAS, the heterogeneity of craniofacial lesions (N = 35) was assessed using a combination of 18F-NaF PET, MRI, and CT. A k-means clustering algorithm was used to categorize lesions based on imaging characteristics. Clustering analysis revealed three types of lesion based on the magnitude of the regional 18F-NaF standardized uptake values (SUV), signal intensities on T1-weighted and fluid-sensitive sequences, and appearance on CT (lucent, sclerotic, and/or ground glass). This preliminary study provides a foundation for future longitudinal natural history or treatment studies, where the prognostic value of baseline craniofacial fibrous dysplasia imaging characteristics and clinical symptomatology can be further evaluated.

Coexistence of meningioma and craniofacial fibrous dysplasia: a case series of clinicopathological study and literature review

BACKGROUND

The co-existence of meningioma and craniofacial fibrous dysplasia (CFD) is rare. Due to the similar radiological characteristics, it is challenging to differentiate such co-existence from solitary hyperostotic meningioma resulting in a dilemma of prompt diagnosis and appropriate intervention.

METHOD

We conducted a retrospective review of the data from 21 patients with concomitant meningioma and CFD who were treated at Beijing Tiantan Hospital from 2003 to 2021. We summarized their clinicopathological features and performed a comprehensive literature review. Additionally, we tested the characteristic pathogenic variants in exon 8 and 9 of GNAS gene and the expression of corresponding α-subunit of the stimulatory G protein (Gαs) related to CFD to explore the potential interactions between these two diseases.

RESULTS

The cohort comprised 4 men and 17 women (mean age, 45.14 years). CFD most commonly involved the sphenoid bone (n = 10) and meningiomas were predominantly located at the skull base (n = 12). Surgical treatment was performed in 4 CFD lesions and 14 meningiomas. Simpson grade I-II resection was achieved in 12 out of the 14 resected meningiomas and almost all of them were classified as WHO I grade (n = 13). The mean follow-up duration was 56.89 months and recurrence was noticed in 2 cases. Genetic study was conducted in 7 tumor specimens and immunohistochemistry was accomplished in 8 samples showing that though GNAS variant was not detected, Gαs protein were positively expressed in different degrees.

CONCLUSIONS

We presented an uncommon case series of co-diagnosed meningioma and CFD and provided a detailed description of its clinicopathological features, treatment strategy and prognosis. Although a definite causative relationship had not been established, possible genetic or environmental interplay between these two diseases could not be excluded. It was challenging to initiate prompt diagnosis and appropriate treatment for concomitant meningioma and CFD because of its similar radiological manifestations to meningioma with reactive hyperostosis. Personalized and multi-disciplinary management strategies should be adopted for the co-existence of meningioma and CFD.

Multimodal imaging diagnosis for bone fibrous dysplasia malignant transformation: A case report

Fibrous dysplasia of bone (FDB) is a rare benign condition in which fibrous tissue replaces normal bone architecture. FDB rarely undergoes malignant transformation, but there are reports of locally aggressive fibrous dysplasia with cortical destruction and soft tissue extension. Diagnosis of FDB malignant transformation is not easy, especially in monostotic form, because of the overlap in imaging features of locally aggressive fibrous dysplasia and fibrous dysplasia with malignant transformation. The present case study reports a rare case of FDB in a 23-year-old man with polyostotic fibrous dysplasia arising in the left side of the pelvis and lower limb bones with partial transformation to fibrosarcoma. This study explored the multimodal imaging features of FDB malignant transformation, to achieve early detection and improve diagnostic accuracy of local FDB aggressiveness and its malignant transformation.

A practical overview of CT and MRI features of developmental, inflammatory, and neoplastic lesions of the sphenoid body and clivus

The sphenoid bone is an unpaired bone that contributes to the formation of the skull base. Despite the enormous progress in transnasal endoscopic visualisation, imaging techniques remain the cornerstones to characterise any pathological condition arising in this area. In the present review, we offer a bird's-eye view of the developmental, inflammatory, and neoplastic alterations affecting the sphenoid body and clivus, with the aim to propose a practical diagnostic aid for radiologists based on clinico-epidemiological, computed tomography, and magnetic resonance imaging features.

Pediatric Petrous Apex Lesions: A Radiological Classification and Diagnostic Algorithm

The petrous apex (PA) is involved in a myriad of pathological conditions, some of which are exclusive in children. Diagnosis may be difficult due to vague clinical presentation, and local examination is challenging owing to its inaccessible location. This is further complicated by multiple unfused sutures and ongoing PA pneumatization in children. Cross-sectional imaging is vital for the evaluation of the PA lesions, due to their precarious location and proximity to the major neurovascular structures. Several classification systems have been proposed for these lesions based on their site of origin, solid or cystic appearance, surgical or non-surgical (no touch lesions) management, and benign or malignant nature. In this article, we emphasize the distinctive role of different cross-sectional imaging modalities in the diagnosis of pediatric PA lesions, with special attention to normal variants that should not be mistaken for pathology. We also propose a radiological classification and algorithmic approach to aid in the precise diagnosis and facilitate appropriate management of the various PA lesions in children.

New technologies in oral radiology as a diagnostic aid for monostotic fibrous dysplasia: a review

Monostotic fibrous dysplasia is a benign asymptomatic lesion that affects only one bone, which is replaced by amorphous connective tissue. Clinically there is an increase in the volume of the affected area, which is observed by imaging as a radiopaque area with diffuse non-corticalized limits capable of expanding to neighboring structures, and it is histologically evidenced as "resembling Chinese characters". The lesion is seen as a radiopaque image with diffuse borders in conventional or digital radiography, while cone beam computed tomography identifies the exact location and extension of an isodense, mixed or hyperdense image of non-corticalized edges. Magnetic resonance imaging is also used when the lesion involves soft tissues or nerves, and bone scintigraphy is performed in order to systemically observe bone quality. The objective of this article was to describe the new technologies in oral radiology for the diagnosis of monostotic fibrous dysplasia and the importance of the current imaging methods in achieving an adequate diagnosis. These techniques range from conventional radiography to bone scans, which provide images of higher quality, clarity and better precision with less invasive techniques to the patient. This review of the literature helps to expand the knowledge of dental professionals in relation to the clinical and imaging characteristics of monostotic fibrous dysplasia.

The Skinner Burial of Ontario, Canada, and the Question of Paget's Disease in the Americas

PURPOSE

To examine a possible case of Paget's disease of bone (PDB) in an Indigenous pre-contact male from Canada, individual D of the Skinner site in Ontario.

METHODS

Radiographs, CT scan and histological analysis.

RESULTS

The histological analysis revealed the mosaic pattern that characterizes PDB. CT scans show advanced sclerosis of the cranium and a diminished diplӧe with osteolytic lesions.

CONCLUSIONS

The pathological features that have been identified are collectively characteristic of PDB.

SIGNIFICANCE

The Skinner case advances our understanding of the global history and distribution of PDB.

LIMITATIONS OF STUDY

Only two New World cases have been identified and neither has been studied in sufficient detail.

SUGGESTIONS FOR FUTURE RESEARCH

The older individuals in precolonial New World skeletal series should be given CT scans, which are non-intrusive, to be followed by histological and genetic analyses when indicated.

Auxological and Endocrinological Features in Children With McCune Albright Syndrome: A Review

McCune-Albright syndrome is a rare and challenging congenital sporadic disease involving the skin and skeletal and endocrine systems with a prevalence ranges from one in 100,000 to 1,000,000. In addition to the classical triad of fibrous dysplasia of bone, café au lait pigmented skin lesions and precocious puberty, other multiple endocrinological features, including hyperthyroidism, growth hormone excess, hypercortisolism, and hypophosphatemic rickets, have been reported. A brief review of the syndrome in children is here reported.

Radiological manifestations of renal osteodystrophy in the orofacial region: a case report and literature review

Renal osteodystrophy (ROD) is a metabolic skeletal pathology that frequently affects the orofacial region and presents with characteristic radiological manifestations. This paper reports a case of ROD causing diffused orofacial bone alterations in a female patient with end-stage chronic kidney disease. The radiological features on panoramic, posteroanterior and lateral skull and computed tomography radiographs are described for this case. Previous reports in the literature are reviewed and discussed with a focus on radiological characteristics and differential diagnoses.

Fibrous dysplasia for radiologists: beyond ground glass bone matrix

Fibrous dysplasia (FD) is a congenital disorder arising from sporadic mutation of the α-subunit of the Gs stimulatory protein. Osseous changes are characterised by the replacement and distortion of normal bone with poorly organised, structurally unsound, fibrous tissue. The disease process may be localised to a single or multiple bones. In McCune-Albright syndrome (MAS), fibrous dysplasia is associated with hyperfunction of endocrine organs and overproduction of melanin in the skin, while Mazabraud syndrome FD is associated with intramuscular myxomas. In radiology, FD is very often automatically associated with the term "ground glass matrix". However, FD is a complex disease, and knowledge of its unique pathogenesis and course are crucial to understanding imaging findings and potential complications. This article aims to not only summarise the spectrum of radiological findings of osseous and extra-osseous abnormalities associated with FD but also to highlight the pathological base of the disease evolution, corresponding imaging changes and complications based on the disease distribution. We also have provided current recommendations for clinical management and follow-up of patients with FD. TEACHING POINTS: • FD is often a part of complex disease, involving not only bone but also multiple other organs. • FD lesions are characterised by age-related histological, radiographical and clinical transformations. • Radiologists play a crucial role in the identification of osseous complications associated with FD. • The craniofacial form of the disease is the most common type of FD and the most difficult form to manage. • Patients with McCune-Albright syndrome may have different extra-skeletal abnormalities, which often require follow-up.

Magnetic resonance imaging features of craniofacial fibrous dysplasia

Purpose

To assess the value of magnetic resonance imaging (MRI) in detecting craniofacial fibrous dysplasia (CFD) and diagnosing and differentiating it from intraosseous meningioma. Additionally, the MRI appearance of the typical computed tomography (CT) imaging feature, the ground glass phenomenon, was evaluated.

Material and methods

MRI datasets of 32 patients with CFD were analysed retrospectively. Detectability in MRI was assessed by analysis of 10 randomly selected patients with CFD and 10 normal controls by two blinded readers. Changes of affected bone, internal lesion structure, T1 and T2 signal intensity, and contrast enhancement of the lesion in general and ground glass areas in particular were assessed. Ten patients with intraosseous meningioma (one in each) served as differential diagnosis for CFD.

Results

All 10 CFD lesions were reliably detected in MRI. In 32 patients 36 CFD lesions were evaluated. In 66.7% CFD were iso- to hypointense in T1 and hyperintense in T2; this proportion was similar for ground glass areas (65.7%). Ground glass areas were more homogeneously structured than the whole CFD lesion in both T1 (100% vs. 56%, respectively) and T2 (91% vs. 61%, respectively). Contrast enhancement was found in 97% of complete CFD lesions and 93% of ground glass areas. The accuracy for CFD vs. intraosseous meningioma was 100% for 'no soft-tissue component' and 98% for 'bone broadening' in MRI.

Conclusions

Distinct morphological changes of CFD are reliably detected in MRI and allow differentiation from intraosseous meningioma. Areas with ground glass phenomenon in CT show a predominantly homogenous internal structure in MRI with contrast enhancement.

Craniofacial Manifestations of Systemic Disorders: CT and MR Imaging Findings and Imaging Approach

Many systemic diseases or conditions can affect the maxillofacial bones; however, they are often overlooked or incidentally found at routine brain or head and neck imaging performed for other reasons. Early identification of some conditions may significantly affect patient care and alter outcomes. Early recognition of nonneoplastic hematologic disorders, such as thalassemia and sickle cell disease, may help initiate earlier treatment and prevent serious complications. The management of neoplastic diseases such as lymphoma, leukemia, or Langerhans cell histiocytosis may be different if diagnosed early, and metastases to the maxillofacial bones may be the first manifestation of an otherwise occult neoplasm. Endocrinologic and metabolic disorders also may manifest with maxillofacial conditions. Earlier recognition of osteoporosis may alter treatment and prevent complications such as insufficiency fractures, and identification of acromegaly may lead to surgical treatment if there is an underlying growth hormone-producing adenoma. Bone dysplasias sometimes are associated with skull base foraminal narrowing and subsequent involvement of the cranial nerves. Inflammatory processes such as rheumatoid arthritis and sarcoidosis may affect the maxillofacial bones, skull base, and temporomandibular joints. Radiologists should be familiar with the maxillofacial computed tomographic and magnetic resonance imaging findings of common systemic disorders because these may be the first manifestations of an otherwise unrevealed systemic process with potential for serious complications. Online supplemental material is available for this article. ^©RSNA, 2018.