Cherubism: clinical evidence and therapy

Surgical management of severe cherubism persisting into early adulthood: a case report and literature review

Cherubism is a rare fibro-osseous condition characterized by bilateral expansion of the mandible and maxilla. Due to its rarity, treatment guidelines for cherubism have not been clearly established. Observation without surgical intervention is typically recommended, as cherubism often regresses spontaneously after puberty. However, a surgical intervention may be necessary if aggressive lesions lead to severe complications. In this report, we present a case involving surgical management of cherubism that did not spontaneously regress until early adulthood. An 18-year-old man was diagnosed with cherubism, presenting characteristic upward-looking eyes and a swollen face. He strongly desired surgical management. Gross contouring of the mandible was performed using an osteotome. Subsequently, delicate contouring was performed by bone burring and curettage. The remaining multiple locular bony defects were filled with demineralized bone matrix. No major complications, including infection and hematoma, occurred during the 8-month follow-up period. The facial contour remained stable without the aggravation of cherubism. The patient was satisfied with the cosmetic results. Considering that cherubism is a rare disease globally, with few reported cases in Korea, and that treatment guidelines are not clearly established, we anticipate that the results of this case will contribute to the development of future protocols for treating cherubism.

Multiple versus solitary giant cell lesions of the jaw: Similar or distinct entities?

The majority of giant cell lesions of the jaw present as a solitary focus of disease in bones of the maxillofacial skeleton. Less frequently they occur as multifocal lesions. This raises the clinical dilemma if these should be considered distinct entities and therefore each need a specific therapeutic approach. Solitary giant cell lesions of the jaw present with a great diversity of symptoms. Recent molecular analysis revealed that these are associated with somatic gain-of-function mutations in KRAS, FGFR1 or TRPV4 in a large component of the mononuclear stromal cells which all act on the RAS/MAPK pathway. For multifocal lesions, a small group of neoplastic multifocal giant cell lesions of the jaw remain after ruling out hyperparathyroidism. Strikingly, most of these patients are diagnosed with jaw lesions before the age of 20 years, thus before the completion of dental and jaw development. These multifocal lesions are often accompanied by a diagnosis or strong clinical suspicion of a syndrome. Many of the frequently reported syndromes belong to the so-called RASopathies, with germline or mosaic mutations leading to downstream upregulation of the RAS/MAPK pathway. The other frequently reported syndrome is cherubism, with gain-of-function mutations in the SH3BP2 gene leading through assumed and unknown signaling to an autoinflammatory bone disorder with hyperactive osteoclasts and defective osteoblastogenesis. Based on this extensive literature review, a RAS/MAPK pathway activation is hypothesized in all giant cell lesions of the jaw. The different interaction between and contribution of deregulated signaling in individual cell lineages and crosstalk with other pathways among the different germline- and non-germline-based alterations causing giant cell lesions of the jaw can be explanatory for the characteristic clinical features. As such, this might also aid in the understanding of the age-dependent symptomatology of syndrome associated giant cell lesions of the jaw; hopefully guiding ideal timing when installing treatment strategies in the future.

Late reactivation of cherubism in an adult further to local inflammation

Cherubism is a rare pediatric disease affecting the jaw. It appears among children between 2 and 5 years old. Maximum growth is observed at 7-8 years old, then lesions remain unchanged or increase slowly until puberty. Only 2 cases of later growth have been reported. We describe a case of cherubism reactivation in a 46-year-old woman. Appearance of a new lesion occurs in a context of local inflammation due to repeated friction of the dental prosthesis on the mandible. No article in the literature describes a similar case. This case shows the determining role of inflammation (local or general) in the pathophysiology of cherubism.

Ophthalmic manifestations of cherubism

Cherubism is a rare craniofacial disorder characterized by progressive replacement of mandibular and maxillary bone with multicystic fibro-osseous tissue, potentially resulting in significant deformity and morbidity. The severity of the disorder is variable; more advanced disease may affect the orbit and impact vision. We detail the ophthalmological findings in 2 patients, 7 and 8 years of age, with cherubism.

Cherubism: panoramic and CT features in adults

OBJECTIVES

To describe the panoramic radiographic and CT features of cherubism in an unselected series of 15 adults.

METHODS

In this cross-sectional study, 15 individuals aged 29-84 years with familial non-syndromal molecularly confirmed cherubism were examined with panoramic radiography and CT. Bone abnormalities were analysed and described.

RESULTS

11 (73%) of the 15 adults had mandibular abnormalities. These abnormalities ranged from subtly detectable to severe, and were less prevalent and expansive but could be rather similar to the characteristic image features in children. Unilocular radiolucencies were more common than multilocular radiolucencies, and a specific feature of these abnormalities was that they were exclusively found in the anterior mandible.

CONCLUSIONS

The radiographic and CT abnormalities of cherubism in adults were frequent and extremely heterogeneous, with some distinct features.

SH3BP2 mutations potentiate osteoclastogenesis via PLCγ

To determine the mechanism for the increased osteoclastogenesis in the jaw of cherubism patients with SH3BP2 mutations we evaluated the effect of mutant compared to wild-type SH3BP2 on activation of osteoclast signaling pathways. Indeed mutant forms of SH3BP2 do induce greater osteoclastogenesis. Heterozygous activating mutations in exon 9 of SH3BP2 have been found in most patients with cherubism, an unusual genetic syndrome characterized by excessive remodeling of the mandible and maxilla due to spontaneous and excessive osteoclastic bone resorption. Here we have investigated the functional consequences of SH3BP2 mutations on sRANKL-induced osteoclastogenesis in RAW 264.7 pre-osteoclast cells. sRANKL-stimulated RAW 264.7 cells were transfected with wild-type or mutant SH3BP2 plasmids. NFAT-luciferase and tartrate resistant acid phosphatase (TRAP), a marker of osteoclastic differentiation, levels were evaluated. Western immunoblots were also performed to determine phosphorylation of key proteins involved in the PI-PLC pathway leading to NFATc1 translocation. Our results indicate that forced expression of mutant forms of SH3BP2, found in cherubism patients, in RAW 264.7 cells induce greater NFAT activity and greater expression of TRAP than forced expression of wild-type SH3BP2. These findings indicate that missense SH3BP2 mutations cause a gain of protein function. Moreover, over expression of SH3BP2 in RAW 264.7 cells potentiates sRANKL-stimulated phosphorylation of PLCγ1 and PLCγ2. Our studies demonstrate that cherubism is due to gain-of-function mutations in SH3BP2 that stimulate RANKL-induced activation of PLCγ. The consequent activation of calcineurin and NFAT proteins induces the excessive osteoclastic phenotype of cherubism.

Cherubism: clinicoradiographic features and treatment

Objectives

Cherubism is a congenital childhood disease of autosomal dominant inheritance. This disease is characterized by painless bilateral enlargement of the jaws, in which bone is replaced with fibrous tissue. The condition has sui generis clinical, radiographic and histological features, of which the clinician should be aware for a better differential diagnosis in the presence of a fibro-osseous lesion affecting the bones of the maxillomandibular complex. The purpose of present paper was to review the literature and to report the most important aspects of cherubism in order to facilitate the study of this disease

Material and Methods

Literature was reviewed about cherubism, emphasizing the relevant clinicoradiographic features and treatment. Literature was selected through a search of PubMed and Scielo electronic databases. The keywords used for search were adolescent, cherubism, cherubism/physiopathology, cherubism/treatment, cherubism/radiography. A manual search of the reference lists of the identified articles and the authors' article files and recent reviews was conducted to identify additional publications. Those studies that described new features about cherubism were included in this review.

Results

In total 44 literature sources were obtained and reviewed. Studies that described new features about cherubism physiopathology, diagnostics and treatment were reviewed.

Conclusions

Despite the exceptions, cherubism is a clinically well-characterized disease. In cases of a suspicion of cherubism, radiographic examination is essential since the clinical presentation, the location and distribution of the lesions may define the diagnosis. Histopathological examination is complementary. Nowadays, genetic tests should be used for final diagnosis of cherubism.

Clinical Practice: Giant Cell Tumour of the Jaw Mimicking Bone Malignancy on Three-Dimensional Computed Tomography (3D CT) Reconstruction

A wide range of diseases may present with radiographic features of osteolysis. Periapical inflammation, cysts and benign tumours, bone malignancies, all of these conditions may show bone resorption on radiograph. Features of the surrounding bone, margins of the lesion, and biological behaviour including tendency to infiltration and root resorption, may represent important criteria for distinguishing benign tumours from their malign counterpart, although the radiographic aspect of the lesion is not always predictive. Therefore a critical differential diagnosis has to be reached to choose the best management. Here, we report a case of giant cell tumour (GCT) whose radiological features by computed tomography (CT) suggested the presence of bone malignancy, whereas the evaluation of a routine OPT scan comforted us about the benign nature of the lesion. A brief review of the literature on such a benign but locally aggressive neoplasm is also provided.

SH3BP2 is an activator of NFAT activity and osteoclastogenesis

Heterozygous activating mutations in exon 9 of SH3BP2 have been found in most patients with cherubism, an unusual genetic syndrome characterized by excessive remodeling of the mandible and maxilla due to spontaneous and excessive osteoclastic bone resorption. Osteoclasts differentiate after binding of sRANKL to RANK induces a number of downstream signaling effects, including activation of the calcineurin/NFAT (nuclear factor of activated T cells) pathway. Here, we have investigated the functional significance of SH3BP2 protein on osteoclastogenesis in the presence of sRANKL. Our results indicate that SH3BP2 both increases nuclear NFATc1 in sRANKL treated RAW 264.7 preosteoclast cells and enhances expression of tartrate resistant acid phosphatase (TRAP), a specific marker of osteoclast differentiation. Moreover, overexpression of SH3BP2 in RAW 264.7 cells potentiates sRANKL-stimulated phosphorylation of PLCgamma1 and 2, thus providing a mechanistic pathway for the rapid translocation of NFATc1 into the nucleus and increased osteoclastogenesis in cherubism.

Diagnostic potential of 3D-data-based reconstruction software: an analysis of the rare disease pattern of cherubism

Cherubism is an autosomal-dominant syndrome characterized by bilateral maxillomandibular bony degeneration, fibrous connective tissue hyperplasia, and displacement of permanent tooth germs. Reossification of the cystic lumen occurs spontaneously, but dislocated teeth must be realigned orthodontically. Advancements in virtual 3D reconstruction of anatomic structures based on computed tomography (CT) or cone beam CT data have provided for more predictable individual treatment planning. We evaluated two software programs for making densitometry and volume measurements of cystic areas in the mandibles, and for 3D visualization of permanent tooth germs within the cystic lumen, in two siblings with cherubism.

Morphological and clinical considerations of first and second permanent molar eruption disorders

Tooth eruption is a complex biological process which starts from the site of development in the jaw bone until the teeth reach their final functional position in the chewing plane. Various factors can disturb this process. Besides mechanical obstacles on the eruption path, a pathological position or axial orientation of the tooth germ, morphological aberrations of the tooth or pathological alterations of the periodontium, primary disorders of the eruption mechanism may lead to complete or partial retention of the tooth in the jaw bone. These morphological features bear upon the prognosis of orthodontic correction which is dependent upon the underlying cause. First and second molars are rarely affected by eruption disorders, with a prevalence of 0.01 to 0.08 per cent, however, marked consequences for function such as posterior open bite or elongation of the antagonists may result. Following an overview of pathogenetic factors of tooth eruption disorders, selected cases of impacted first and second permanent molars are presented with respect to their morphological causes.

Cherubism: a clinical, radiographic, and histopathologic comparison of 7 cases

PURPOSE

Cherubism is an uncommon fibro-osseous disorder of the jaws that presents with varying degrees of involvement and a tendency toward spontaneous remission. Lesions are characterized by replacement of bone with fibrovascular tissue containing abundant multinucleated giant cells. We attempted to study the relationships among the degree of cherubism, the radiographic extent of the jaw lesions, the histopathologic findings, and the clinical course of 7 patients.

PATIENTS AND METHODS

In 7 patients diagnosed with cherubism, we evaluated the degree of fibrosis and perivascular cuffing, the presence of focal hemosiderin deposits, and giant multinucleated cell density (absent, few, moderate, or severe). Clinical course and progression were also assessed using a 4-point scale (improvement, no changes, modest progression, and marked progression).

RESULTS

The patients were followed up for an average of 8.5 years. Two patients exhibited clinical and radiographic improvement, while 3 showed no changes, and 2 progressed despite surgical treatment in 1 of them.

CONCLUSION

The course of cherubism in 1 of our patients may represent evidence of an association between the presence of abundant multinucleated giant cells, an increased extent of the lesions, and a more aggressive behavior of the disease.

Aggressive behaviour of cherubism in a teenager: 4-years of clinical follow-up associated with radiographic and histological features

Cherubism is a rare hereditary fibro-osseous childhood disease characterized by bone degradation and fibrous tissue replacement at the angles of the mandible and at the tuberosity areas of the maxilla that leads to prominence of the lower face and an appearance reminiscent of the cherub's portrayal in Renaissance art. This disease has an autosomal dominant hereditary characteristic. The purpose of this report is to analyse laboratory tests, clinicopathological and radiographic features of cherubism and its intraoral manifestations in a patient during 4-years of follow-up, correlating the features observed in this case with those of the literature. Also discussed is the atypical and aggressive behaviour of this case during puberty.

Lesions of the maxilla

The maxilla may be involved by a wide range of pathologic conditions. Lesions originating in the maxilla may involve the adjacent orbit, oral cavity, or retroantral spaces. Recognition of this relationship plays an important role in diagnosis, prognosis, and presurgical planning.