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Frontiers in Veterinary Science 2022Ameloblastoma is a benign epithelial odontogenic tumor with the capacity to aggressively invade the surrounding bone. Surgical removal of the tumor can result in... (Review)
Review
Ameloblastoma is a benign epithelial odontogenic tumor with the capacity to aggressively invade the surrounding bone. Surgical removal of the tumor can result in extended disease-free interval (cure). However, controversy surrounds the most appropriate surgical margin required to prevent local recurrence while simultaneously minimizing morbidity. excisional surgery carries the risk of major complications such as mandibular drift, hemorrhage, and oronasal fistula formation. Conservative therapy without a safety margin reduces potential morbidity but is likely to result in local recurrence. No reliable rate, nor time to recurrence, is documented but may be as high as 91% with conservative therapy. Conversely, surgery with a 10- to 20-mm margin is associated with a 0-4.6% recurrence rate. There is no documented difference in the recurrence rate with a 10- vs. 20-mm margin. The correlation of the histologic margin with the recurrence rate following excisional surgery has not determined a required histologic safety margin. Rather, no local recurrence occurs despite narrow or incomplete margins. Thus, pathologic margins > 0 mm may be sufficient to prevent local recurrence or recurrence may be protracted. Accordingly, a narrow (5-10 mm) gross surgical margin may be the most appropriate. Additional research is required for confirmation, and only level 4 evidence on safety margins has been achieved thus far. Future work should focus on defining the extension of neoplastic cells past the demarcation of ameloblastoma on variable diagnostic imaging modalities as well as determining the recurrence rate with various surgical and histologic safety margins.
PubMed: 35392113
DOI: 10.3389/fvets.2022.830258 -
Head and Neck Pathology Sep 2021Unicystic ameloblastoma (UA) is an uncommon variant of ameloblastoma and behaves totally different from the solid multicystic variant of ameloblastoma (SMA); furthermore... (Comparative Study)
Comparative Study
Clinicopathological Profile of 80 Cases of Unicystic Ameloblastoma Aided by a Histopathological Comparison Using Modified Philipsen-Reichart Classification and Marx-Stern Classification.
Unicystic ameloblastoma (UA) is an uncommon variant of ameloblastoma and behaves totally different from the solid multicystic variant of ameloblastoma (SMA); furthermore the histological subgroups of UA also show varied behavior regarding proliferation. The present multi-centric study was designed to present the clinicopathological features of unicystic ameloblastoma (UA) and to compare the two popular histological classifications systems. 80 satisfactory cases of UA were retrieved and evaluated for clinicopathological parameters from four teaching dental schools of North India. The cases were classified using modified Reichart and Philipsen system and Marx and Stern system followed by comparison of inter-observer variability. The results were analyzed using SPSS software. The mean age of occurrence was 30.79 ± 16.49 years. Males outnumbered females (M:F::1.67:1). The majority of cases occurred in the third decade irrespective of the gender. Most cases were found in body-angle-ramus region of the mandible. The modified Reichart and Philipsen classification yielded better interobserver agreement (kappa value 0.845). The modified Reichart and Philipsen classification yields better inter-rater agreement and is easy to reproduce amongst oral pathologists. Being simpler it may easily be understood by the operating surgeon for better treatment outcome.
Topics: Adolescent; Adult; Aged; Ameloblastoma; Child; Female; Humans; Jaw Neoplasms; Male; Middle Aged; Observer Variation; Retrospective Studies; Young Adult
PubMed: 33638761
DOI: 10.1007/s12105-021-01307-7 -
Journal of Oral Biology and... 2023Metastasizing Ameloblastoma (MA) is an aggressive variant of ameloblastoma (AM) with the ability to metastasize without cytological malignant changes. Thus it aims to... (Review)
Review
BACKGROUND
Metastasizing Ameloblastoma (MA) is an aggressive variant of ameloblastoma (AM) with the ability to metastasize without cytological malignant changes. Thus it aims to comprehensively review the clinico-pathological and prognostic aspects of MA through integration of current literature.
METHODS
Electronic searches were conducted in PubMed-MEDLINE, Scopus, Web of Science and Google Scholar. Two independent reviewers screened abstracts and evaluated paper eligibility. AMSTAR2 checklist was used to assessed methodological quality of included systematic reviews (SRs).
RESULTS
From 390 initial papers, 279 underwent eligibility screening, with five systematic reviews (SRs) meeting inclusion criteria. Six hundred sixty-one MA cases were found in five SRs that were included. MA predominantly affects men, exhibits mandible preference, and occurs in individuals in their fourth or fifth decade. Benign metastatic deposits commonly manifest in lungs and lymph nodes. Distant metastasis probability rises with multiple recurrences and incomplete surgical removal. Tumor recurrence and metastasis unfavorably impact clinical outcomes. Quality of evidence assessment was absent across SRs; four SRs were critically low in methodological quality.
CONCLUSIONS
AM's metastatic potential lacks predictability. Early/multiple recurrences post-treatment may signal poor prognosis, warranting vigilant follow-up. Methodical analysis of each AM case is imperative to comprehend the metastatic-benign histology relationship.
PubMed: 38028232
DOI: 10.1016/j.jobcr.2023.10.006 -
Journal of Conservative Dentistry : JCD 2022The objective of the study is to describe the clinical and radiographic features of nonmalignant nonendodontic periapical lesions (NMNPLs) mimicking lesions of... (Review)
Review
The objective of the study is to describe the clinical and radiographic features of nonmalignant nonendodontic periapical lesions (NMNPLs) mimicking lesions of endodontic cause. Five electronic databases, PubMed, Web of Science, Scopus, Embase, and ProQuest, were searched (till July 2021) for case reports, case series, and cross-sectional studies, in English language, reporting NMNPLs, which were clinically and/or radiographically simulating periapical pathosis of endodontic origin. Data extraction was done followed by quality assessment of the included articles using the Joanna Briggs Institute tool for case reports and case series. Seventy-three articles comprising 176 cases were included. Sixty-one articles were case reports, nine articles were case series, and three articles were retrospective studies. Male:female ratio was 1.5:1, with a higher prevalence of lesions occurring in the fourth and second decades of life. The majority of the lesions were located in the anterior maxilla. Radiographically, most of the lesions were well defined, radiolucent, and unilocular. Histologically, 29 different types of NMNPLs were reported, with the most common ones being odontogenic keratocyst (25.56%), dentigerous cyst (17.61%), ameloblastoma (11.36%), nasopalatine duct cyst (10.79%), and adenomatoid odontogenic tumor (5.68%). As all the included studies were observational, the quality of available evidence is considered low. Various features such as loss of tooth vitality, history of trauma, and presence of periapical radiolucency may lead to misdiagnosis of NMNPLs and must be considered during diagnosis of the lesion. Additional imaging modalities and histopathology can aid in right diagnosis.
PubMed: 35836562
DOI: 10.4103/jcd.jcd_13_22 -
Scientific Reports Oct 2020Ameloblastomas are epithelial odontogenic tumours that, although benign, are locally invasive and may exhibit aggressive behaviour. In the tumour microenvironment, the...
Ameloblastomas are epithelial odontogenic tumours that, although benign, are locally invasive and may exhibit aggressive behaviour. In the tumour microenvironment, the concentration of oxygen is reduced, which leads to intratumoral hypoxia. Under hypoxia, the crosstalk between the HIF-1α, MMP-2, VEGF, and VEGFR-2 proteins has been associated with hypoxia-induced angiogenesis, leading to tumour progression and increased invasiveness. This work showcases 24 ameloblastoma cases, 10 calcifying odontogenic cysts, and 9 dental follicles, used to investigate the expression of these proteins by immunohistochemistry. The anti-HIF-1α, anti-MMP-2, anti-VEGF, and anti-VEGFR-2 primary antibodies are used in this work. The results have been expressed by the mean grey value after immunostaining in images acquired with an objective of 40×. The ameloblastoma samples showed higher immunoexpression of HIF-1α, MMP-2, VEGF, and VEGFR-2 when compared to the dental follicles and calcifying odontogenic cysts. Ameloblastomas show a higher degree of expression of proteins associated with intratumoral hypoxia and proangiogenic proteins, which indicates the possible role of these proteins in the biological behaviour of this tumour.
Topics: Ameloblastoma; Biomarkers; Dental Sac; Disease Progression; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Immunohistochemistry; Matrix Metalloproteinase 2; Neoplasm Invasiveness; Neovascularization, Pathologic; Odontogenic Tumors; Prognosis; Tumor Microenvironment; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2
PubMed: 33067558
DOI: 10.1038/s41598-020-74693-7 -
Head and Neck Pathology Jun 2022Adenoid ameloblastoma is a hybrid odontogenic tumour showing histopathological features of both ameloblastoma and adenomatoid odontogenic tumour (AOT), with... (Review)
Review
Adenoid ameloblastoma is a hybrid odontogenic tumour showing histopathological features of both ameloblastoma and adenomatoid odontogenic tumour (AOT), with approximately 40 cases reported in the literature. The aims of the report are to illustrate the diagnostic challenges of adenoid ameloblastoma using three new cases and to analyze evidence in literature to consider adenoid ameloblastoma as a new sub type of ameloblastoma. A literature review was performed with the key words-adenoid ameloblastoma, hybrid/composite odontogenic tumours, hybrid ameloblastoma and adenomatoid odontogenic tumour, ameloblastoma with inductive changes, dentinoid and dentinoma to select the cases compatible with the diagnosis of adenoid ameloblastoma. Out of the 40 cases reported in literature, 31 cases with sufficient information and 3 new cases were analyzed. Out of the 34 adenoid ameloblastomas majority of tumours (76.5%) occurred in adults with age ranging from 25 to 55 years. Slight female predilection with a male:female ratio of 0.9:1 was observed. Approximately, 64.7% occurred in the mandible. Radiologically, 82.4% of adenoid ameloblastomas presented as radiolucent lesions while 47.1% occurred with ill-defined margins and cortical perforation at diagnosis. Histopathologically, 70.8% of tumours presented as plexiform ameloblastomas, while duct like structures/glandular structures were the commonest feature supportive of adenomatoid odontogenic tumour observed in overwhelming majority of 95.9% of adenoid ameloblastomas. 91.6% of tumours showed inductive change in the form of dentinoid. Further, 45.4% of the tumours developed at least one recurrence following surgical excision. The report presents literature review based evidence to show the existence of adenoid ameloblastoma, which is demographically similar to conventional ameloblastoma but with histopathological differences and presenting with higher rate/multiple recurrences, indicating its biological aggressiveness. Thus, we would like to propose the inclusion of adenoid ameloblastoma as a sub type of ameloblastoma in the next revision of the WHO odontogenic tumour classification.
Topics: Adenoids; Adult; Ameloblastoma; Female; Humans; Male; Mandible; Middle Aged; Odontogenic Tumors
PubMed: 34282559
DOI: 10.1007/s12105-021-01358-w -
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 -
Case Reports in Plastic Surgery & Hand... Feb 2021We studied 21 patients who underwent radical ameloblastoma excision followed by immediate reconstruction. Comorbidities, consumption of alcohol and/or tobacco and BMI...
We studied 21 patients who underwent radical ameloblastoma excision followed by immediate reconstruction. Comorbidities, consumption of alcohol and/or tobacco and BMI status did not contribute to an unfavorable outcome. Giant ameloblastoma (≥5 cm) and/or tumor involving bony curvatures increased surgical complexity, the incidence of complications and hospital stay.
PubMed: 33681413
DOI: 10.1080/23320885.2021.1886854 -
Ear, Nose, & Throat Journal Dec 2021Ameloblastoma (AM) is a slow growing and aggressive benign tumor with an odontogenic epithelial origin arising from the mandible or maxilla. The odontogenic neoplasm...
Ameloblastoma (AM) is a slow growing and aggressive benign tumor with an odontogenic epithelial origin arising from the mandible or maxilla. The odontogenic neoplasm invades local tissues asymptomatically and accounts for 1% of oral tumors and over 10% of odontogenic tumors. A 64-year-old man with a history of allergic fungal rhinosinusitis (AFRS) undergoing a revision image-guided endoscopic sinus surgery was found to have a fibrous mass suspicious of malignancy projecting inferolaterally and attached to the floor of the left maxillary sinus. Diagnostic biopsies were taken, and additional surgery was required to successfully resect the tumor via a transnasal endoscopic dissection. Multiple permanent pathology samples concluded the diagnosis of an AM. Endoscopic investigations led to the incidental discovery and ultimate complete endoscopic resection of the AM. The utilization of an endoscopic resection compared to the traditional maxillectomy with reconstruction results in significant less short and long-term morbidity for the patient.
Topics: Ameloblastoma; Humans; Male; Maxillary Sinus; Maxillary Sinus Neoplasms; Medical Illustration; Middle Aged; Natural Orifice Endoscopic Surgery; Nose
PubMed: 32484411
DOI: 10.1177/0145561320930555 -
Medicina Oral, Patologia Oral Y Cirugia... Sep 2022Ep-CAM, a transmembrane glycoprotein expressed in most epithelium in normal conditions, has diverse roles in these tissues, including in cell adhesion, proliferation,...
BACKGROUND
Ep-CAM, a transmembrane glycoprotein expressed in most epithelium in normal conditions, has diverse roles in these tissues, including in cell adhesion, proliferation, differentiation, cell cycle regulation, migration and intracellular signaling. It is also over-expressed in most malignant neoplasia, participating in the initiation, progression, and metastatic dissemination of the tumor. The expression and roles of this protein in oral neoplasia, particularly in odontogenic tumors, remain unestablished. The objective of this study consisted in analyzing the expression of this protein in ameloblastoma and tooth germ.
MATERIAL AND METHODS
Ep-CAM (MOC-31) expression was evaluated by immunohistochemistry in tooth germs (TG) (n = 16) ameloblastomas (AM) (n = 60) and 2 ameloblastic carcinomas. Sections were visualized in their totality with an optical microscope, and positivity observed in cell membrane and cytoplasm was graded according to the following semi-quantitative scale: Neg, "essentially unstained", for negative sections or staining <5% of cells; + for staining of 5-50% of cells; ++ for staining >50% of cells.
RESULTS
Most tooth germs expressed MOC-31 (81.3%), strong staining was observed both in the inner epithelium of the enamel organ and in the adjacent stellate reticulum. 16.7% of the AM cases showed MOC-31 expression, the immunoexpression expression was diffuse at the cytoplasmic and membrane level. The only two cases of ameloblastic carcinoma included were strong positive to MOC-31. No correlation was observed between protein expression and gender, age, clinical variants, or histological subtypes.
CONCLUSIONS
Overexpression was found in TG and ameloblastic carcinoma compared to AM; further studies with different experimental strategies are suggested to clarify the biological significance of this finding.
Topics: Ameloblastoma; Carcinoma; Epithelial Cell Adhesion Molecule; Humans; Odontogenic Tumors; Tooth Germ
PubMed: 35975801
DOI: 10.4317/medoral.25145