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Head and Neck Pathology Mar 2022The 5 edition of the World Health Organization (WHO) Classification of Head and Neck Tumours (2022) comes out only five years after the previous edition, however it...
The 5 edition of the World Health Organization (WHO) Classification of Head and Neck Tumours (2022) comes out only five years after the previous edition, however it presents important updates that run in parallel with the rapid progression involving the increasingly sophisticated molecular investigation and its interpretation, some of which already have therapy-related impact. This manuscript provides an overview of the leading changes introduced in the classification of Odontogenic and Maxillofacial Bone Tumours that encompasses cysts of the jaws, odontogenic tumours, giant cell lesions and bone cysts, and bone and cartilage tumours. This is the first edition that Essential and Desirable Diagnostic Features were added for each entity, so that the most important clinical, microscopic and/or radiologic features were encapsulated and briefly highlighted. Surgical ciliated cyst was added to the group of odontogenic cysts, adenoid ameloblastoma was a newly recognized benign epithelial odontogenic tumour, and segmental odontomaxillary dysplasia was introduced in the group of fibro-osseous tumours and dysplasia. In addition, rhabdomyosarcoma with TFCP2 rearrangement, was introduced into the group of malignant jawbone tumours. The unique genetic aberrations distinguish it from other types of rhabdomyosarcomas. On the other hand, melanotic neuroectodermal tumour of infancy and osteoid osteoma were deleted from the benign bone and cartilageneous tumours, as was the hematolymphoid tumour of solitary plasmacytoma of bone. We systematically reviewed each entity in this chapter and provided important updated findings for selected topics that can further aid in the diagnostic process for challenging cases, broaden insights on the logic of the present classification, and finally, emphasize the potential that some of the molecular results may have in the near future to set new treatment approaches.
Topics: Bone Neoplasms; DNA-Binding Proteins; Head and Neck Neoplasms; Humans; Odontogenic Cysts; Odontogenic Tumors; Transcription Factors; World Health Organization
PubMed: 35312978
DOI: 10.1007/s12105-021-01404-7 -
Cancers Nov 2022The discovery that ameloblastoma has a high mutation incidence of V600E may enable a better investigation of pathophysiology. However, there is inconsistent evidence... (Review)
Review
The discovery that ameloblastoma has a high mutation incidence of V600E may enable a better investigation of pathophysiology. However, there is inconsistent evidence regarding this mutation occurrence and its association with clinical information. This systematic review and meta-analysis aim to pool the overall mutation prevalence of V600E in reported ameloblastoma cases and to determine its association with patient demographic and clinicopathological features. Following the PRISMA guidelines, a comprehensive article search was conducted through four databases (Scopus, Google Scholar, PubMed, and Web of Science). Seventeen articles between 2014 and 2022 met the inclusion criteria with 833 ameloblastoma cases. For each included study, the significance of V600E on the outcome parameters was determined using odd ratios and 95% confidence intervals. Meta-analysis prevalence of V600E in ameloblastoma was 70.49%, and a significant meta-analysis association was reported for those younger than 54 years old and in the mandible. On the contrary, other factors, such as sex, histological variants, and recurrence, were insignificant. As a result of the significant outcome of V600E mutation in ameloblastoma pathogenesis, targeted therapy formulation can be developed with this handful of evidence.
PubMed: 36428683
DOI: 10.3390/cancers14225593 -
Journal of Clinical Medicine Jan 2023Sinonasal ameloblastoma (SNA) is considered to be a subtype of ameloblastoma. It differs from gnathic ameloblastoma in terms of clinicopathologic features, management... (Review)
Review
Sinonasal ameloblastoma (SNA) is considered to be a subtype of ameloblastoma. It differs from gnathic ameloblastoma in terms of clinicopathologic features, management and prognosis. Thus, the objective of the present review was to study the complications, survival, recurrence rate and outcomes following the management of SNA. The electronic search process was conducted on PubMed-Medline, Embase, and Scopus. Google Scholar was used to search grey literature. Quality assessment of the case reports (CR) and case series (CS) was done based on CARE guidelines. The initial search resulted in 2111 articles. 15 studies (13 CR and 2 CS) were found to meet the eligibility criteria. The majority of the studies described histological features of SNA, which were consistent with ameloblastomas of gnathic origin. There were no SNA-related deaths reported in the included studies. Five studies described endoscopic surgeries to remove SNAs, and three SNAs were treated with post-surgery radiotherapy. Data from included studies suggest that sinonasal ameloblastomas are histologically similar to gnathic ameloblastomas, but their clinical presentation is different. They may cause complete or partial obstruction of the nasal cavity and the sinus. They appear to affect an older demographic, and their resection may be accompanied by the excision of a large portion of the maxilla, necessitating maxillofacial prosthetic rehabilitation.
PubMed: 36615180
DOI: 10.3390/jcm12010381 -
Asian Pacific Journal of Cancer... Nov 2022Ameloblastoma is regarded as the second most prevalent odontogenic tumor in the light of its prevalence, clinical characteristics, greater incidence of tumor recurrence,... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Ameloblastoma is regarded as the second most prevalent odontogenic tumor in the light of its prevalence, clinical characteristics, greater incidence of tumor recurrence, and therapeutic challenges. The aim of this systematic review was to establish the prevalence of ameloblastoma in the Indian subcontinent and to establish a national epidemiologic profile for these lesions.
MATERIAL AND METHODS
A systematic review was undertaken based on the PRISMA guidelines in search of epidemiologic studies concerning odontogenic tumors and ameloblastoma that are listed by PubMed, EBSCO, and Google Scholar embracing the period from January 2010 to December 2021, to evaluate the prevalence rate in India. A total of 277 publications were retrieved, of which 27 articles were selected, based on the World Health Organization classification of odontogenic tumors.
RESULTS
The affected individuals were on average in the third decade of life, with a higher male predominance. The majority of the tumors were multilocular radiolucencies in the posterior mandible, with follicular and plexiform histopathological features. The most common type of malignant lesion is ameloblastic carcinoma. Over 60% of follicular ameloblastoma recurred more frequently than the other types of ameloblastoma.The random effect model shows overall point estimate of 4.83 with 95% confidence interval (4.44 -5.26).
CONCLUSION
The systematic study indicates a slight male predisposition to ameloblastoma, with a peak incidence in the third decade of life and the mandible as the preferred anatomical site. The solid/multicystic ameloblastoma is the most prevalent histopathologic pattern. More epidemiological research on the prevalence rate of ameloblastoma is required, particularly in India, in an effort to accurately determine the national epidemiological profile of ameloblastoma.
Topics: Male; Humans; Female; Ameloblastoma; Prevalence; India; Odontogenic Tumors; Genotype
PubMed: 36444570
DOI: 10.31557/APJCP.2022.23.11.3601 -
Sultan Qaboos University Medical Journal Aug 2023Papilliferous keratoameloblastoma (PKA) is a rare entity, and not much is known about its clinicodemographic features or biological nature. This review aimed to provide... (Review)
Review
Papilliferous keratoameloblastoma (PKA) is a rare entity, and not much is known about its clinicodemographic features or biological nature. This review aimed to provide clarity regarding the characterisation of the demographic, clinical, radiological and histopathological features of PKA. Case reports of PKA were identified through a systematic search across multiple databases. The search yielded a total of 10 cases, half of which were of Indian origin. All the cases invariably occurred in the mandibular posterior region and involved the right side; only one case primarily involved the left side of the mandible. PKA should be considered a variant of the conventional ameloblastoma that is towards the more aggressive end of the spectrum. It tends to occur in older individuals (in their fifth decade or older), with a marked propensity to occur in the right mandibular posterior region. Surgical resection with diligent follow-up is warranted in the treatment of PKA.
Topics: Humans; Aged; Ameloblastoma; Mandible; Thorax
PubMed: 37655071
DOI: 10.18295/squmj.5.2023.021 -
Sultan Qaboos University Medical Journal Aug 2022This article aimed to collectively present the demographic, clinical, radiographic and histopathological features as well as the treatment performed along with its... (Review)
Review
This article aimed to collectively present the demographic, clinical, radiographic and histopathological features as well as the treatment performed along with its outcome for all the cases of adenoid ameloblastoma with dentinoid (AAD) reported in scientific literature till date. Ameloblastoma and adenomatoid odontogenic tumours are the most common odontogenic neoplasms. However, AAD, a hybrid variant of the two lesions, is found to be extremely rare. The lesion comprises of characteristic histopathological features of ameloblastoma and adenomatoid odontogenic tumour and shares certain clinical characteristics with either of the entities. AAD may be considered to be present at the more aggressive end of spectrum of benign odontogenic neoplasms. Owing to the frequent tendency of the lesions to be underdiagnosed, careful histopathological screening of submitted biopsies is warranted. With the increase in number of reported cases in the recent years, it is likely to be included as a separate entity in the upcoming World Health Organization classification.
Topics: Adenoids; Ameloblastoma; Biopsy; Humans; Odontogenic Tumors
PubMed: 36072074
DOI: 10.18295/squmj.9.2021.127 -
Journal of Oral Pathology & Medicine :... Aug 2022To investigate and compare the demographic data, occurrence of recurrence and metastasis, and survival prognosis between ameloblastic carcinoma (AC) and metastasizing... (Review)
Review
PURPOSE
To investigate and compare the demographic data, occurrence of recurrence and metastasis, and survival prognosis between ameloblastic carcinoma (AC) and metastasizing ameloblastoma (MA), based on appropriate and currently accepted eligible diagnostic criteria, in a systematic review of the literature.
METHODS
An electronic search was undertaken, last updated in December 2021. Eligibility criteria included publications having enough clinicopathological information to confirm the diagnosis of these tumors.
RESULTS
Seventy-seven publications reporting 85 ACs and 43 MAs were included. Both tumors were more frequent in mandible and showed different clinical profiles regarding patients' sex and age. There was no difference in the estimated cumulative survival between patients diagnosed with these tumors. Metastases mainly affected the lungs, followed by cervical lymph nodes. The mean time between the first metastasis and the last follow-up was higher for MA (p = 0.021). In addition, MA patients remained alive longer than AC patients after the first metastasis diagnosis (p = 0.041). Considering only the cases that metastasized, a higher ratio of AC patients died in comparison to MA patients (p = 0.003). The occurrence of recurrence was associated with a conservative primary treatment with both AC (p < 0.001) and MA tumors (p = 0.017). Multiple recurrent events were associated with conservative primary therapies with MA (p < 0.001) but not with AC (p = 0.121).
CONCLUSION
In addition to some demographic differences, ACs that metastasize present a worse prognosis than MA. As conservative procedures are associated with multiple recurrent events, this treatment modality should be avoided for both tumors.
Topics: Ameloblastoma; Carcinoma; Humans; Mandible; Mandibular Neoplasms; Odontogenic Tumors
PubMed: 35822408
DOI: 10.1111/jop.13334 -
Frontiers in Oral Health 2021To perform a comprehensive and systematic critical appraisal of the genetic alterations reported to be present in adenomatoid odontogenic tumor (AOT) compared to...
To perform a comprehensive and systematic critical appraisal of the genetic alterations reported to be present in adenomatoid odontogenic tumor (AOT) compared to ameloblastoma (AM), to aid in the understanding in their development and different behavior. An electronic search was conducted in PubMed, Scopus, and Web of Science during March 2021. Eligibility criteria included publications on humans which included genetic analysis of AOT or AM. A total of 43 articles reporting 59 AOTs and 680 AMs were included. Different genomic techniques were used, including whole-exome sequencing, direct sequencing, targeted next-generation sequencing panels and TaqMan allele-specific qPCR. Somatic mutations affecting were identified in 75.9% of all AOTs, mainly G12V; whereas a 71% of the AMs harbored mutations, mainly V600E. The available genetic data reports that AOTs and AM harbor somatic mutations in well-known oncogenes, being KRAS G12V/R and BRAFV600E mutations the most common, respectively. The relatively high frequency of ameloblastoma compared to other odontogenic tumors, such as AOT, has facilitated the performance of different sequencing techniques, allowing the discovery of different mutational signatures. On the contrary, the low frequency of AOTs is an important limitation for this. The number of studies that have a assessed the genetic landscape of AOT is still very limited, not providing enough evidence to draw a conclusion regarding the relationship between the genomic alterations and its clinical behavior. Thus, the presence of other mutational signatures with clinical impact, co-occurring with background mutations or in wild-type cases, cannot be ruled out. Since BRAF and RAS are in the same MAPK pathway, it is interesting that ameloblastomas, frequently associated with BRAFV600E mutation have aggressive clinical behavior, but in contrast, AOTs, frequently associated with RAS mutations have indolent behavior. Functional studies might be required to solve this question.
PubMed: 35048068
DOI: 10.3389/froh.2021.767474 -
Indian Journal of Dental Research :... 2022Ameloblastoma is a benign, locally aggressive neoplasm that needs extensive surgical resection. The goal of this article is to obtain an in-depth review of benign... (Review)
Review
Ameloblastoma is a benign, locally aggressive neoplasm that needs extensive surgical resection. The goal of this article is to obtain an in-depth review of benign ameloblastomas to determine the available level of evidence and the possible benefit of targeted therapeutics for the treatment of ameloblastoma and BRAF V600E mutation in ameloblastoma. An electronic literature search was conducted according to PRISMA guidelines in PubMed/MEDLINE, EBSCO, and Web of Science for eligible studies published between 1975 and 2021. The systematic review is registered with INPLASY (INPLASY202260018). The review included 2 case series and 17 case reports. The histopathological type, anatomic location, expression of BRAF mutation, additional mutations, and molecular-targeted therapies of the 19 reviewed articles were summarized and tabulated. Interestingly, the majority of the primary site of ameloblastoma was located in the mandible (80.9%) compared to the maxilla (17%). The tumour size was reported in nine of the included studies. Most of the included studies in the review exhibited ameloblastoma with BRAF V600E mutations and responded to molecular-targeted therapies. Molecular therapies employing BRAF and/or MEK inhibitors in ameloblastoma with BRAF V600E mutations proved to be an appropriate treatment based on the limited available evidence. It is essential further to deepen our understanding at the clinical and molecular level to enhance the precision of management of ameloblastoma.
Topics: Humans; Ameloblastoma; Molecular Targeted Therapy; Mutation; Proto-Oncogene Proteins B-raf
PubMed: 36656197
DOI: 10.4103/ijdr.ijdr_456_22 -
Journal of Current Ophthalmology Mar 2018Ameloblastoma is a non-encapsulated and slow-growing tumor with high recurrence rate. Orbital involvement by this neoplasm is an extremely rare entity. In this study, we... (Review)
Review
PURPOSE
Ameloblastoma is a non-encapsulated and slow-growing tumor with high recurrence rate. Orbital involvement by this neoplasm is an extremely rare entity. In this study, we present a systematic review on this situation along with clinical and paraclinical features of a case.
METHODS
An electronic search was conducted on major medical sources. Data of the cases in the literature in addition to our own case were extracted, summarized, and statistically analyzed.
RESULTS
A total of 36 other cases from 20 relevant studies were also reviewed. Review topics included epidemiology, clinical presentation, pathologic features, differential diagnosis, imaging, treatment, and prognosis. We provided a five-year history of a 50-year-old man with orbital/skull base invasion of plexiform maxillary ameloblastoma.
CONCLUSIONS
Maxillary ameloblastoma is a locally aggressive neoplasm, and physicians must be alert to the biologic behavior of this tumor to detect any invasion to critical structures such as orbit and cranium. Orbital ameloblastoma causes significant morbidity and mortality. We advocate meticulous patient follow-up with regular clinical examinations and paraclinical work-up for timely detection of any invasion or recurrence. The best must be done to avoid extensions by aggressive removal of maxillary ameloblastoma.
PubMed: 29564405
DOI: 10.1016/j.joco.2017.09.001