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Journal of Clinical and Experimental... May 2019Ameloblastic fibroma (AF) and ameloblastic fibro-odontoma (AFO) are uncommon benign mixed odontogenic neoplasms. Although unusual microscopic changes including hybrid... (Review)
Review
BACKGROUND
Ameloblastic fibroma (AF) and ameloblastic fibro-odontoma (AFO) are uncommon benign mixed odontogenic neoplasms. Although unusual microscopic changes including hybrid tumors have been documented in publications, their clinical outcome prediction and treatment modality selection are still challenging due to scarcity. Objective: Analysis of AF/AFO's unusual microscopic variants in order to improve histopathologic diagnosis and to help clinicians in making informed treatment choices.
MATERIAL AND METHODS
An electronic search was performed in PubMed's database using keywords: "ameloblastic fibroma", "ameloblastic fibroodontoma", "ameloblastic fibro-odontoma". The search scheme was limited to articles in English, dated 'January 1998' to 'October 2018', with full texts (case reports and series) and human studies. Eligibility criteria included publications having enough clinical, radiological, and histological data to confirm their diagnosis. Age, sex, lesions' location, radiologic features, signs, symptoms, treatment approaches, and recurrences were recorded and analyzed.
RESULTS
In this systematic review, 11 articles (reporting 14 cases) were selected. Patients' mean age was 13.75 years (male/female = 1.8). The posterior region of the mandible was the lesions' commonest location (57.14%). Swelling was reported in 78.57% of the cases, pain in 28.57% but 21.42% were asymptomatic. Radiolucent unilocular appearance was the commonest radiographic feature, but 28.57% of the cases showed a mixed radiolucent-radiopaque appearance. Other reported radiographic findings were impacted tooth (78.57%), root resorption (28.57%), tooth mobility (35.71%), and cortical perforation (14.28%). No recurrences were reported. Calcifying odontogenic cyst (COC) was the commonest lesion associated with AF/AFO (53.33%). Unicystic ameloblastoma and cystic changes without prominent epithelial lining were other reported hybrid lesions. Reported microscopic variations were pigmentation and ghost cell differentiation.
CONCLUSIONS
COC was the commonest lesion associated with AF/AFO. Although COC commonly occurs in the jaws' anterior region, hybrid cases were more common in the posterior area. No malignant transformations were reported. The treatment modality is mostly chosen based on the lesion's most aggressive part. Ameloblastic fibroma, Ameloblastic fibro-odontoma, Odontogenic tumor, Jaw.
PubMed: 31275522
DOI: 10.4317/jced.55460 -
Journal of Oral and Maxillofacial... 2023Ameloblastoma is a benign tumour of odontogenic epithelial origin arising from enamel organ tissue that has not undergone differentiation to the point of hard tissue...
BACKGROUND
Ameloblastoma is a benign tumour of odontogenic epithelial origin arising from enamel organ tissue that has not undergone differentiation to the point of hard tissue formation.
AIMS
This study was conducted with an aim to provide a baseline data to analyse whether various histopathological variants of ameloblastoma satisfies all the characteristic histopathological features of Vickers and Gorlin criteria.
SETTINGS AND DESIGN
A retrospective study of 25 cases of intraosseous ameloblastoma was carried out in the Department of Oral Pathology and Microbiology in accordance with the Institutional Ethics Committee.
METHODS AND MATERIALS
Histopathological slides of ameloblastoma subtypes were analysed microscopically to assess Vickers and Gorlin criteria.
STATISTICAL ANALYSIS USED
Statistical analysis was done using the Chi-square test. A value of < 0.05 was set for statistical significance.
RESULTS
Presence of hyperchromatic nuclei was seen in all the variants (100%), except for the desmoplastic variant which showed only 60% positivity. Basal cell palisading, reverse polarity and subnuclear vacuolization were seen predominantly only in acanthomatous (100%), and follicular variants (83%).
CONCLUSIONS
Vickers and Gorlin criteria have become an integral part of diagnosis of histopathological subtypes of ameloblastoma and should be applied vigilantly in the diagnosis as these may not always fulfill all the gold standard criteria when individual subtypes are assessed.
PubMed: 38033969
DOI: 10.4103/jomfp.jomfp_186_23 -
Journal of Clinical and Diagnostic... Nov 2015Ameloblastoma is a benign but aggressive odontogenic neoplasm arising from odontogenic epithelium. Many theories have been proposed to explain the pathogenesis of... (Review)
Review
Ameloblastoma is a benign but aggressive odontogenic neoplasm arising from odontogenic epithelium. Many theories have been proposed to explain the pathogenesis of ameloblatoma. Numerous signalling pathways have been implicated to be associated in the development and progression of this neoplasm. Studies have found association of various signalling molecules of Sonic Hedgehog Pathway, namely SHH, PTCH1, SMO, Gli 1, Gli 2, Gli 3, with ameloblastoma. Knowledge about this pathway will help us to understand the nature and behaviour of this neoplasm. This will open the door towards new treatment modalities.
PubMed: 26674664
DOI: 10.7860/JCDR/2015/15443.6750 -
Matrix Biology Plus Dec 2022Tumour development and progression is dependent upon tumour cell interaction with the tissue stroma. Bioengineering the tumour-stroma microenvironment (TME) into 3D...
Tumour development and progression is dependent upon tumour cell interaction with the tissue stroma. Bioengineering the tumour-stroma microenvironment (TME) into 3D biomimetic models is crucial to gain insight into tumour cell development and progression pathways and identify therapeutic targets. Ameloblastoma is a benign but locally aggressive epithelial odontogenic neoplasm that mainly occurs in the jawbone and can cause significant morbidity and sometimes death. The molecular mechanisms for ameloblastoma progression are poorly understood. A spatial model recapitulating the tumour and stroma was engineered to show that without a relevant stromal population, tumour invasion is quantitatively decreased. Where a relevant stroma was engineered in dense collagen populated by gingival fibroblasts, enhanced receptor activator of nuclear factor kappa-B ligand (RANKL) expression was observed and histopathological properties, including ameloblastoma tumour islands, developed and were quantified. Using human osteoblasts (bone stroma) further enhanced the biomimicry of ameloblastoma histopathological phenotypes. This work demonstrates the importance of the two key stromal populations, osteoblasts, and gingival fibroblasts, for accurate 3D biomimetic ameloblastoma modelling.
PubMed: 36452176
DOI: 10.1016/j.mbplus.2022.100125 -
Cancer Medicine Apr 2020Ameloblastoma is a rare odontogenic benign tumor accounting for less than 1% of head and neck tumors. Advanced next generation sequencing (NGS) analyses identified high...
Ameloblastoma is a rare odontogenic benign tumor accounting for less than 1% of head and neck tumors. Advanced next generation sequencing (NGS) analyses identified high frequency of BRAF V600E and SMO L412F mutations in ameloblastoma. Despite the existence of whole genomic sequence information from patients with ameloblastoma, entire molecular signature of and the characteristics of ameloblastoma cells are still obscure. In this study, we sought to uncover the molecular basis of ameloblastoma and to determine the cellular phenotype of ameloblastoma cells with BRAF mutations. Our comparative cDNA microarray analysis and gene set enrichment analysis (GSEA) showed that ameloblastoma exhibited a distinct gene expression pattern from the normal tissues: KRAS-responsive gene set is significantly activated in ameloblastoma. Importantly, insulin like growth factor 2 (IGF2), a member of KRAS-responsive genes, enhances the proliferation of an ameloblastoma cell line AMU-AM1 with BRAF mutation. In addition, Toll-like receptor 2 (TLR2) knockdown readily inactivated KRAS-responsive gene sets as well as increases caspase activities, suggesting that TLR2 signaling may mediate cell survival signaling in ameloblastoma cells. Collectively, the findings may help to further clarify the pathophysiology of ameloblastoma and lead to the development of precision medicine for patients with ameloblastoma.
Topics: Adult; Aged; Ameloblastoma; Biomarkers, Tumor; Cell Proliferation; Child; Female; Follow-Up Studies; Gene Expression Regulation, Neoplastic; Humans; Jaw Neoplasms; Male; Middle Aged; Mutation; NF-kappa B; Prognosis; Toll-Like Receptor 2; Transcriptome; Tumor Cells, Cultured
PubMed: 32096304
DOI: 10.1002/cam4.2931 -
Medicina Oral, Patologia Oral Y Cirugia... Nov 2023Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative... (Review)
Review
BACKGROUND
Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative frequency of odontogenic tumours in a Chilean population using the 2022 World Health Organization classification.
MATERIAL AND METHODS
This is a case series retrospective study. We reviewed 35,530 samples from 1975 to 2022 from the Oral Pathology Referral Institute and the Pathological Anatomy Service, Faculty of Dentistry, University of Chile. We utilized the 2022 World Health Organization classification for histological typification.
RESULTS
According to 2022 World Health Organization classification, 544 odontogenic tumours were confirmed. The most frequent odontogenic tumours were: odontoma (n=241; 44.3%), ameloblastoma (n=109; 20.0%) and cemento-ossifying fibroma (n=71; 13.1%). Benign odontogenic tumours corresponded to 538 cases (98.9%) and malignant tumours were only six cases (1.1%).
CONCLUSIONS
In our population, odontoma was the most frequent odontogenic tumour followed by ameloblastoma and cemento-ossifying fibroma. Malignant odontogenic tumours were very rare. The results of this study are similar to reports from America, but there are some differences concerning the data from Africa and Asia.
Topics: Humans; Ameloblastoma; Odontoma; Retrospective Studies; Cementoma; Chile; Odontogenic Tumors; World Health Organization
PubMed: 37823289
DOI: 10.4317/medoral.26008 -
International Journal of Molecular... Jun 2019Ameloblastoma is a common odontogenic benign tumor located in the jaws and is characterized by severe local bone destruction. The current study aimed to investigate the...
Ameloblastoma is a common odontogenic benign tumor located in the jaws and is characterized by severe local bone destruction. The current study aimed to investigate the effect of interactions between tumor cells and bone marrow stromal cells (BMSCs) on osteoclast formation in ameloblastoma. The impact of ameloblastoma/BMSC interactions on cytokine production, gene expression and osteoclastogenesis was examined using an immortalized ameloblastoma cell line that the authors' previously established. The results demonstrated that interactions between ameloblastoma cells and BMSCs increased interleukin (IL)‑8 and activin A secretion by BMSCs. IL‑8 expression in BMSCs was modulated by tumor‑derived tumor necrosis factor‑α and IL‑8 contributed to osteoclast formation not only directly but also by stimulating receptor activator of NF‑κB ligand (RANKL) expression in BMSCs. Activin A secretion in BMSCs was stimulated by ameloblastoma cells via cell‑to‑cell‑mediated activation of c‑Jun N‑terminal kinase activation, acting as a cofactor of RANKL to induce osteoclast formation and function. The present study highlights the critical role of communication between BMSCs and ameloblastoma cells in bone resorption in ameloblastoma.
Topics: Activins; Adult; Ameloblastoma; Cells, Cultured; Female; Gene Expression Regulation, Neoplastic; Humans; Interleukin-8; Jaw Neoplasms; Male; Mesenchymal Stem Cells; Osteoclasts; Osteolysis; Tumor Cells, Cultured; Up-Regulation; Young Adult
PubMed: 31017256
DOI: 10.3892/ijmm.2019.4171 -
Head and Neck Pathology Mar 2023Cystic lesions of the gnathic bones present challenges in differential diagnosis. This category includes a smorgasbord of odontogenic and non-odontogenic entities that... (Review)
Review
BACKGROUND
Cystic lesions of the gnathic bones present challenges in differential diagnosis. This category includes a smorgasbord of odontogenic and non-odontogenic entities that may be reactive or neoplastic in nature. While most cystic jaw lesions are benign, variability in biologic behavior makes distinction between these entities absolutely crucial.
METHODS
Review.
RESULTS
Two clinical cases are presented in parallel and are followed by an illustrated discussion of the ten most likely differential diagnoses that should be considered when confronted with a cystic jaw lesion. Strong emphasis is placed on the histologic differences between these entities, empowering readers to diagnose them with confidence. Perhaps even more importantly, the more common diagnostic pitfalls in gnathic pathology are discussed, recognizing that a definitive diagnosis cannot be rendered in every situation. The histologic diagnoses for the two clinical cases are finally revealed.
CONCLUSION
Cystic lesions of the maxilla and mandible may be odontogenic or non-odontogenic. The most common cystic lesions are the reactive periapical cyst, and the dentigerous cyst (which is developmental in nature). It is important to note that cystic neoplasms also occur in the jaws, and that the presence of inflammation may obscure the diagnostic histologic features of lesions like odontogenic keratocyst and unicystic ameloblastoma. Ancillary testing is of limited diagnostic value in most scenarios. However, both clinical and radiographic information (such as the location, size, duration, associated symptoms, and morphology of the lesion in its natural habitat) are significantly useful.
Topics: Humans; Diagnosis, Differential; Jaw Neoplasms; Odontogenic Cysts; Odontogenic Tumors; Ameloblastoma; Maxilla
PubMed: 36928736
DOI: 10.1007/s12105-023-01525-1 -
Cancer Diagnosis & Prognosis 2023Tumors and cysts with odontogenic origin represent a family of lesions with specific histo-genetic and clinical characteristics. Among them, ameloblastomas are common... (Review)
Review
Tumors and cysts with odontogenic origin represent a family of lesions with specific histo-genetic and clinical characteristics. Among them, ameloblastomas are common benign neoplasms, predominantly detected in the anatomic areas of the jaws and also in the mandible and maxilla. Although they are characterized by a slow and stable growing pattern, a subset of them shows a tendency for local tissue invasiveness and partially increased recurrence rates after surgical excision. Furthermore, heat shock proteins (HSPs) are potentially implicated in ameloblastoma onset and progression. HSPs regulate the folding and refolding of proteins and are induced in response to oxidative stress. They are crucial members of the chaperone intracellular system and are categorized based on their molecular weight (i.e., HSP27, HSP60, HSP70, HSP90). In the current review, we describe HSPs origin and function, focusing on their deregulation mechanisms and impact predominantly on ameloblastomas and also on inflammatory and developmental odontogenic cystic lesions.
PubMed: 37927807
DOI: 10.21873/cdp.10265 -
Journal of Taibah University Medical... Feb 2022This study aims to determine the histopathological patterns and biological characteristics of ameloblastoma.
OBJECTIVES
This study aims to determine the histopathological patterns and biological characteristics of ameloblastoma.
METHODS
This was a cross-sectional retrospective laboratory-based study using 82 formalin-fixed paraffin-embedded tissue blocks from patients diagnosed histologically with ameloblastoma. Information regarding age, sex, anatomical location of the lesion, histopathologic type, and biological behaviour or characteristics of the types of ameloblastoma was obtained from laboratory request forms. Categorical and continuous variables were summarized in percentage and mean ± standard deviation, respectively. The cohort was conducted on Ugandan patients diagnosed between 2016 and 2019.
RESULTS
Most patients (66.3%) were clinically presenting a painless jaw swelling, and a follicular pattern was common (39%) followed by the plexiform pattern (12.2%). All the ameloblastoma cases (100%) were benign, with the majority (76.8%) cases being non-recurrent while the remaining (23.2%) were recurrent, and the plexiform pattern was the commonest recurrent histopathological pattern.
CONCLUSION
This study reports a relatively significant rate of recurrence in almost a quarter of the study population. The plexiform histopathologic type was the dominant type in recurrence cases. Therefore, this finding provides insightful information to clinicians to ensure close follow-up for patients diagnosed with such a variant to prevent possible relapse of the disease.
PubMed: 35140571
DOI: 10.1016/j.jtumed.2021.09.007