Familial gigantiform cementoma: distinctive clinical features of a large Chinese pedigree

Familial gigantiform cementoma with recurrent ANO5 p.Cys356Tyr mutations: Clinicopathological and genetic study with literature review

BACKGROUND

Familial gigantiform cementoma (FGC) is a rare tumor characterized by the early onset of multi-quadrant fibro-osseous lesions in the jaws, causing severe maxillofacial deformities. Its clinicopathological features overlap with those of other benign fibro-osseous lesions. FGC eventually exhibits progressively rapid growth, but no suspected causative gene has been identified.

METHODS

In this study, three patients with FGC were recruited, and genomic DNA from the tumor tissue and peripheral blood was extracted for whole-exome sequencing.

RESULTS

Results showed that all three patients harbored the heterozygous mutation c.1067G > A (p.Cys356Tyr) in the ANO5 gene. Furthermore, autosomal dominant mutations in ANO5 at this locus have been identified in patients with gnathodiaphyseal dysplasia (GDD) and are considered a potential causative agent, suggesting a genetic association between FGC and GDD. In addition, multifocal fibrous bone lesions with similar clinical presentations were detected, including five cases of florid cemento-osseous dysplasia, five cases of polyostotic fibrous dysplasia, and eight cases of juvenile ossifying fibromas; however, none of them harbored mutations in the ANO5 gene.

CONCLUSION

Our findings indicate that FGC may be an atypical variant of GDD, providing evidence for the feasibility of ANO5 gene testing as an auxiliary diagnostic method for complex cases with multiple quadrants.

Familial Gigantiform Cementoma: Life-Saving Total Midface Resection and Reconstruction Using Virtual Surgical Planning and 3D Printed Patient-Specific Implant-A Clinical Study

Background

Familial gigantiform cementoma (FGC) is a rare benign fibrocemento-osseous lesion of the jaw characterized by well-circumscribed, extensive, mixed radiolucent-radiopaque masses in the mandible and the maxilla that can cause severe facial deformity. This condition is extremely rare with less than 40 cases reported in the literature.

Purpose

The purpose of the paper is to highlight the importance of virtual surgical planning and patient-specific implant in the treatment of a complex lesion and reconstruction of the facial skeleton. The clinical presentations, and diagnostic challenges encountered when managing the lesion have been discussed in this article with emphasis on the treatment plan.

Method/Surgical plan

The sequence of treatment planned was resection of the lesion and immediate reconstruction with a patient-specific implant to improve the patient's quality of life. The management of FGC was a challenging one keeping in mind the rapid expansion of the lesion, widespread involvement of the jaws, and needs of the pediatric patient.

Conclusion

Virtual surgical planning (VSP) along with 3D printed implant was instrumental in reconstructing the facial form of the child where the maxilla was completely resected and rehabilitation provided support to the vital structures of the face.

Ano5 modulates calcium signaling during bone homeostasis in gnathodiaphyseal dysplasia

ANO5 encodes transmembrane protein 16E (TMEM16E), an intracellular calcium-activated chloride channel in the endoplasmic reticulum. Mutations in ANO5 are associated with gnathodiaphyseal dysplasia (GDD), a skeletal disorder causing the jaw deformity and long bone fractures. However, the coordinated mechanism by which ANO5 mediates bone homeostasis in GDD remains poorly defined. Here, we show that ablation of Ano5 reduced intracellular calcium transients, leading to defects in osteogenesis and osteoclastogenesis and thus bone dysplasia. We found a causative de novo ANO5 frameshift insertion mutation (p.L370_A371insDYWRLNSTCL) in a GDD family with osteopenia, accompanied by a decrease in TMEM16E expression and impaired RANKL-induced intracellular calcium ([Ca²⁺]_i) oscillations in osteoclasts. Moreover, using Ano5 knockout (KO) mice, we found that they exhibited low bone volume, abnormal calcium deposits, and defective osteoblast and osteoclast differentiation. We also showed that Ano5 deletion in mice significantly diminished [Ca²⁺]_i oscillations in both osteoblasts and osteoclasts, which resulted in reduced WNT/β-Catenin and RANKL-NFATc1 signaling, respectively. Osteoanabolic treatment of parathyroid hormone was effective in enhancing bone strength in Ano5 KO mice. Consequently, these data demonstrate that Ano5 positively modulates bone homeostasis via calcium signaling in GDD.

A family of familial gigantiform cementoma: clinical study

Background

Familial gigantiform cementoma is an autosomal dominant fibro-cement osseous lesion that causes massive expansion of facial skeleton. Patients with such massive lesions have a compromised quality of life. The main goal of treating such patients is to restore and preserve the jaw as far as possible which would enhance their quality of life.

Purpose

This study was conducted to identify the occurrence of gigantiform cementoma which had affected three generations of a family and also to focus on documentation of the clinical course and management.

Method

Patients (one family-mother, grandmother, aunt and grandson) who had visited the Department of Oral and Maxillofacial Surgery, Tamilnadu Government Dental College and Hospital, Chennai, over a period for their swelling in the maxillofacial region were clinically and radiographically evaluated and histopathologically diagnosed as familial gigantiform cementoma; later, they were surgically managed.

Result

It is very rare to document three generations of this disease which had shown varied clinical presentation (asymptomatic slow growth, arrested growth and one case of aggressive growth). Management of these cases varied from observation to aggressive resection.

Conclusion

Gigantiform cementoma follows an autosomal dominant pattern of inheritance with variable phenotypic expression without gender predilection. These cases require regular observation and intervention if necessary.

[Clinical and imaging characteristics of familial gigantiform cementoma. A review of the literature]

Familial gigantiform cementoma (FGC) is a rare benign fibro-cementum lesion, which follows an autosomal dominant inheritance pattern and presents during childhood. It is limited to the bones of the face, with a predilection for the jaw, is fast growing and painless and expands considerably over time. It is considered among the seven disorders that affect the physiognomy of the craniofacial skeleton. Radiographically, FGC occurs in three stages of maturation similar to bone dysplasia, being radiolucent, mixed and radiopaque and is described as a mixed lobular well delimited mass, which can occur in both maxillae, causing expansion of the buccal and palatal / lingual bone cortices. displacement and retention of teeth. The aim of this study was to perform a review of the literature to identify the clinical, radiographic and histopathological characteristics of FGC in the jaws and describe the imaging tools that are useful for the diagnosis and follow-up of this lesion.

Familial florid cemento-osseous dysplasia: a report of three cases and review of the literature

Familial cases of benign fibro-osseous lesions of the jaws are rare and have been described under numerous terms including familial gigantiform cementoma, multiple cemento-ossifying fibromas, sclerotic cemental masses and familial florid cemento-osseous dysplasia. The synonymous and interchangeable use of these terms to describe distinct entities with overlapping features has resulted in confusion and inaccurate categorisation of these lesions. This study highlights three family members with diffuse fibro-osseous jaw lesions with areas of significant expansion. In the pursuit of finding the best clinicopathological categorisation for the reported cases, familial florid cemento-osseous dysplasia and familial gigantiform cementoma were investigated. The final consensus of these three cases was that of familial florid cemento-osseous dysplasia, and one patient presented with a concurrent "ossifying fibromatoid lesion". A literature review on the above entities was performed in an attempt to provide clarification and delineate distinguishing features of the individual diseases.

Management strategy in patient with familial gigantiform cementoma: A case report and analysis of the literature

RATIONALE

Familial gigantiform cementoma (FGC) is a rare benign autosomal dominant fibrocemento-osseous lesion generally limited to the facial bones, typically in the anterior portion of the mandible; it is often associated with abnormalities of the long bones and prepubertal pathologic fractures. Owing to the small number of such patients, a uniform treatment criterion has not been established. This paper presents a patient with FGC who was treated in our department, and offers a systematic review of the patients reported in the literature. Our aim was to explore the treatment strategy for patients with FGC.

PATIENT CONCERNS

Our patient, a 13-year-old boy, presented with a painless enlargement of the mandible first noted 2 years earlier. It had grown rapidly over the preceding 8 months, affecting both his appearance and ability to chew.

DIAGNOSIS

Based on the pathologic, clinical, and radiographic features, FGC was diagnosed.

INTERVENTIONS

Mandibuloectomy was performed. The mandibular defect was immediately reconstructed with his right vascularized iliac crest flap. At the same time, a PubMed search was conducted to identify studies reporting on other patients with FGC.

OUTCOMES

A 3-dimensional computed tomography (3D-CT) scan demonstrated appropriate height of the new alveolar bone. Follow-up results showed recovery of the patient's appearance and mandibular function. He was free of recurrence at 4-year follow-up.

LESSONS

FGC is a rare benign fibrocemento-osseous lesion of the jaws that can cause severe facial deformity. Incomplete removal leads to more rapid growth of the residual lesion. Therefore, extensive resection is a suitable strategy to avoid recurrence. Defects of the facial bones found intraoperatively should be repaired with resort to an appropriate donor site. However, it is important to be aware that patients with FGC always have concomitant abnormalities of skeletal metabolism and structure, as well as a vulnerability to fractures of the long bones of the lower extremity. Therefore, the optimal management strategy should include a review of treatment options for other patients as reported in the literature. An optimal protocol can not only provide sufficient high-quality bone suitable for the reconstruction of bone defects, but also minimize complications and maximize quality of life.

Whole exome sequencing links dental tumor to an autosomal-dominant mutation in ANO5 gene associated with gnathodiaphyseal dysplasia and muscle dystrophies

Tumors of the jaws may represent different human disorders and frequently associate with pathologic bone fractures. In this report, we analyzed two affected siblings from a family of Russian origin, with a history of dental tumors of the jaws, in correspondence to original clinical diagnosis of cementoma consistent with gigantiform cementoma (GC, OMIM: 137575). Whole exome sequencing revealed the heterozygous missense mutation c.1067G > A (p.Cys356Tyr) in ANO5 gene in these patients. To date, autosomal-dominant mutations have been described in the ANO5 gene for gnathodiaphyseal dysplasia (GDD, OMIM: 166260), and multiple recessive mutations have been described in the gene for muscle dystrophies (OMIM: 613319, 611307); the same amino acid (Cys) at the position 356 is mutated in GDD. These genetic data and similar clinical phenotypes demonstrate that the GC and GDD likely represent the same type of bone pathology. Our data illustrate the significance of mutations in single amino-acid position for particular bone tissue pathology. Modifying role of genetic variations in another gene on the severity of the monogenic trait pathology is also suggested. Finally, we propose the model explaining the tissue-specific manifestation of clinically distant bone and muscle diseases linked to mutations in one gene.

Central Cemento-Ossifying Fibroma: Primary Odontogenic or Osseous Neoplasm?

Currently, central cemento-ossifying fibroma is classified by the World Health Organization as a primary bone-forming tumor of the jaws. However, histopathologically, it is often indistinguishable from cemento-osseous dysplasias in that it forms osteoid and cementicles (cementum droplets) in varying proportions. It is believed that pluripotent cells within the periodontal membrane can be stimulated to produce either osteoid or woven bone and cementicles when stimulated. If this is true, cemento-ossifying fibroma would be better classified as a primary odontogenic neoplasm arising from the periodontal ligament. Cemento-ossifying fibromas also do not occur in the long bones. The present report compares several entities that fall within the diagnostic realm of benign fibro-osseous lesions and reviews the evidence for reclassifying central cemento-ossifying fibroma as a primary odontogenic neoplasm.