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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 -
Medical Oncology (Northwood, London,... Apr 2023Ameloblastoma in 66% of the cases harbor a somatic mutation of the "mitogen-activated protein kinase" signaling pathway (BRAF V600E). In V600E mutations, BRAF is in the... (Review)
Review
BACKGROUND
Ameloblastoma in 66% of the cases harbor a somatic mutation of the "mitogen-activated protein kinase" signaling pathway (BRAF V600E). In V600E mutations, BRAF is in the permanent "on" state and relays the growth-promoting signals independently of the EGFR pathway. Therefore, mutant BRAF represents a target for handful of new drugs.
METHODS
We conducted a literature search, with the search terms "Vemurafenib, Dabrafenib, Ameloblastoma, and BRAF." These included seven case reports with nine patients who underwent monotherapy with Dabrafenib or Vemurafenib or combination therapy with Dabrafenib and Trametinib.
RESULTS
The patients age ranges from 10 years up to 86 years. The distribution of women and men is 4:5. Patients with an initial diagnosis of ameloblastoma, as well as recurrences or metastasized ameloblastoma were treated. Indications cover neoadjuvant therapy up to the use in metastasized patients in an irresectable state. Results ranging from "only" tumor size reduction to restitutio ad integrum.
CONCLUSION
We see the use of BRAF Inhibitors to reduce tumor size with consecutive surgical treatment as a reasonable option for therapy. However, we are aware that at present the data are based only on case reports with the longest follow-up of just 38 months. We encourage further clinical trials in the use of BRAF Inhibitors for selecting ameloblastoma patients in a multi-center setting.
Topics: Male; Humans; Female; Child; Vemurafenib; Proto-Oncogene Proteins B-raf; Ameloblastoma; Imidazoles; Protein Kinase Inhibitors; Mutation; Antineoplastic Combined Chemotherapy Protocols
PubMed: 37115331
DOI: 10.1007/s12032-023-01993-z -
Frequency of Odontogenic Tumors: A Single Center Study of 1089 Cases in Japan and Literature Review.Head and Neck Pathology Jun 2022Several attempts have been made to classify odontogenic tumors; however, the need for a uniform international classification system led the World Health Organization... (Review)
Review
Several attempts have been made to classify odontogenic tumors; however, the need for a uniform international classification system led the World Health Organization (WHO) to present a classification of odontogenic tumors in 1971. We aimed to evaluate the number and types of odontogenic tumors examined at the Tokyo Dental College Hospital in Japan to determine the frequency and types of odontogenic tumors, based on the 2017 WHO classification system, as this information has not been reported previously in Japan. We also compared the results of our evaluation with those reported in previous studies. We conducted a clinicopathological evaluation of odontogenic tumors examined at the Tokyo Dental College Hospital between 1975 and 2020. This included an analysis of 1089 cases (malignant, n = 10, 0.9%; benign, n = 1079, 99.1%) based on the 2017 World Health Organization Classification of Head and Neck Tumors. We identified 483 (44.3%), 487 (44.7%), and 109 (10.0%) benign epithelial odontogenic, mixed odontogenic, and mesenchymal tumors, respectively. The most common tumor types were odontoma (42.5%) and ameloblastoma (41.9%). Of the 1089 cases, 585 (53.7%) and 504 (46.3%) were male and female patients, respectively. Ameloblastoma and ameloblastic fibroma occurred more commonly in male patients, whereas odontogenic fibroma and cemento-ossifying fibroma affected female patients primarily. The age at diagnosis ranged from three to 87 (mean, 29.05) years. In 319 (29.3%) patients, the age at diagnosis ranged from 10 to 19 years. Ameloblastoma and odontoma were the most common tumor types among patients in their 20s and those aged 10-19 years, respectively. In 737 (67.7%) and 726 (66.7%) patients, the tumors were located in the mandible and posterior region, respectively. Ameloblastoma was particularly prevalent in the posterior mandible. Odontogenic tumors are rare lesions and appear to show a definite geographic variation.
Topics: Ameloblastoma; Female; Fibroma, Ossifying; Humans; Japan; Male; Odontogenic Tumors; Odontoma; Retrospective Studies
PubMed: 34716904
DOI: 10.1007/s12105-021-01390-w -
Diagnostic Pathology May 2011To investigate the expression of CD10 and osteopontin in dentigerous cyst and ameloblastoma and to correlate their expression with neoplastic potentiality of dentigerous...
AIMS AND OBJECTIVES
To investigate the expression of CD10 and osteopontin in dentigerous cyst and ameloblastoma and to correlate their expression with neoplastic potentiality of dentigerous cyst and local invasion and risk of local recurrence in ameloblastoma.
METHODS
CD10 and osteopontin expression was studied by means of immunohistochemistry in 9 cases of dentigerous cysts (DC) and 17 cases of ameloblastoma. There were 7 unicystic ameloblastoma (UCA) and 10 multicystic ameloblastoma (MCA). Positive cases were included in the statistical analysis, carried on the tabulated data using the Open Office Spreadsheet 3.2.1 under Linux operating system. Analysis of variance and correlation studies were performed using "R" under Linux operating system (R Development Core Team (2010). Tukey post-hoc test was also performed as a pair-wise test. The significant level was set at 0.05.
RESULTS
High CD10 and osteopontin expression was observed in UCA and MCA, and low CD10 and osteopontin expression was observed in DC. Significant correlation was seen between CD10 and osteopontin expression and neoplastic potentiality of DC and local invasion and risk of recurrences in ameloblastoma.
CONCLUSIONS
In DC, high CD10 and osteopontin expression may indicate the neoplastic potentiality of certain areas. In UCA & MCA, high CD10 and osteopontin expression may identify areas with locally invasive behavior and high risk of recurrence.
Topics: Ameloblastoma; Biomarkers, Tumor; Dentigerous Cyst; Disease Progression; Humans; Jaw Neoplasms; Neprilysin; Osteopontin
PubMed: 21609487
DOI: 10.1186/1746-1596-6-44 -
The American Journal of Case Reports Jun 2021BACKGROUND Primary malignant ameloblastoma is a very rare tumor of the dental lamina epithelium. Similar to the benign ameloblastoma, the mass is without significant...
BACKGROUND Primary malignant ameloblastoma is a very rare tumor of the dental lamina epithelium. Similar to the benign ameloblastoma, the mass is without significant histological atypia, but the malignant type may present with metastases, most commonly to the lungs. The average age of diagnosis is 34 years, and the malignancy affects men and women equally. The tumors often present with an insidious growth and have a median survival from time of diagnosis of 17.6 years. Due to the rarity of this lesion, a standard of care has not yet been established. CASE REPORT A 38-year-old Haitian woman, who initially presented with a large primary malignant ameloblastoma of the angle of the mandible, experienced a recurrence in the floor of the mouth 30 months after surgical resection. In 2018, 2 years after the removal of the recurrent tumor, the patient presented with ascites, right-sided abdominal pain, weight loss, and a palpable liver mass. Laparoscopic exploration demonstrated a complex lateral right liver lobe cyst, suspicious for parasitic infection. Cytological analysis showed positive staining for cytokeratin 5/6, P63, and CD56, indicative of metastatic ameloblastoma of the liver. Consistent cell morphology from the primary tumor and liver cyst was also noted. Following drainage of the cyst, the patient returned to Haiti, where she died in 2020. In Haiti, she lacked appropriate local medical care, leading to the severe progression of her initial primary ameloblastoma and disease recurrence. CONCLUSIONS Malignant ameloblastoma accounts for less than 2% of all odontogenic tumors, as the benign variant is much more common. Distant metastases of these lesions are rare; to date, few cases have presented with hepatic metastases.
Topics: Adult; Ameloblastoma; Female; Haiti; Humans; Liver Neoplasms; Male; Neoplasm Recurrence, Local; Odontogenic Tumors
PubMed: 34175884
DOI: 10.12659/AJCR.929422 -
International Journal of Oral Science Feb 2024Ameloblastoma is a benign tumor characterized by locally invasive phenotypes, leading to facial bone destruction and a high recurrence rate. However, the mechanisms...
Ameloblastoma is a benign tumor characterized by locally invasive phenotypes, leading to facial bone destruction and a high recurrence rate. However, the mechanisms governing tumor initiation and recurrence are poorly understood. Here, we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution. Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response (IR), bone remodeling (BR), tooth development (TD), epithelial development (ED), and cell cycle (CC) signatures. Of note, we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence, which was dominated by the EZH2-mediated program. Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids. These data described the tumor subpopulation and clarified the identity, function, and regulatory mechanism of CC ameloblastoma cells, providing a potential therapeutic target for ameloblastoma.
Topics: Humans; Ameloblastoma; Neoplasm Recurrence, Local; Phenotype; Cell Transformation, Neoplastic; Gene Expression Profiling
PubMed: 38424060
DOI: 10.1038/s41368-024-00281-4 -
Head and Neck Pathology Dec 2020Peripheral ameloblastoma (PA) is a prototype form of extraosseous odontogenic tumor. As knowledge of PA has accumulated on the basis of more than 200 cases reported... (Review)
Review
Peripheral ameloblastoma (PA) is a prototype form of extraosseous odontogenic tumor. As knowledge of PA has accumulated on the basis of more than 200 cases reported worldwide over a 60-year timeframe, it is important to comprehend the historical evolution of this entity. In 2018, we summarized the American history of PA, stressing the important early strides made by Bloodgood in 1904 with his many original observations of the "epulis form of ameloblastoma". During the preparation of our previous report, we were able to find several earlier and interesting descriptions in the literature. This review covers the early history of PA since the nineteenth century, chronologically focusing on meritorious articles published in the United States and Europe.
Topics: Ameloblastoma; History, 19th Century; History, 20th Century; History, 21st Century; Humans
PubMed: 32451874
DOI: 10.1007/s12105-020-01168-6 -
International Journal of Computer... Mar 2021The differentiation of the ameloblastoma and odontogenic keratocyst directly affects the formulation of surgical plans, while the results of differential diagnosis by...
PURPOSE
The differentiation of the ameloblastoma and odontogenic keratocyst directly affects the formulation of surgical plans, while the results of differential diagnosis by imaging alone are not satisfactory. This paper aimed to propose an algorithm based on convolutional neural networks (CNN) structure to significantly improve the classification accuracy of these two tumors.
METHODS
A total of 420 digital panoramic radiographs provided by 401 patients were acquired from the Shanghai Ninth People's Hospital. Each of them was cropped to a patch as a region of interest by radiologists. Furthermore, inverse logarithm transformation and histogram equalization were employed to increase the contrast of the region of interest (ROI). To alleviate overfitting, random rotation and flip transform as data augmentation algorithms were adopted to the training dataset. We provided a CNN structure based on a transfer learning algorithm, which consists of two branches in parallel. The output of the network is a two-dimensional vector representing the predicted scores of ameloblastoma and odontogenic keratocyst, respectively.
RESULTS
The proposed network achieved an accuracy of 90.36% (AUC = 0.946), while sensitivity and specificity were 92.88% and 87.80%, respectively. Two other networks named VGG-19 and ResNet-50 and a network trained from scratch were also used in the experiment, which achieved accuracy of 80.72%, 78.31%, and 69.88%, respectively.
CONCLUSIONS
We proposed an algorithm that significantly improves the differential diagnosis accuracy of ameloblastoma and odontogenic keratocyst and has the utility to provide a reliable recommendation to the oral maxillofacial specialists before surgery.
Topics: Algorithms; Ameloblastoma; China; Diagnosis, Differential; Humans; Machine Learning; Neural Networks, Computer; Odontogenic Cysts; Radiography; Radiography, Panoramic; Radiologists; Reproducibility of Results; Rotation; Sensitivity and Specificity
PubMed: 33547985
DOI: 10.1007/s11548-021-02309-0 -
BMC Oral Health Aug 2023Ameloblastic carcinoma and metastasising ameloblastoma are rare epithelial odontogenic tumours with aggressive features. Distinguishing between these two lesions is... (Review)
Review
BACKGROUND
Ameloblastic carcinoma and metastasising ameloblastoma are rare epithelial odontogenic tumours with aggressive features. Distinguishing between these two lesions is often clinically difficult but necessary to predict tumour behaviour or to plan future therapy. Here, we provide a brief review of the literature available on these two types of lesions and present a new case report of a young man with an ameloblastoma displaying metastatic features. We also use this case to illustrate the similarities and differences between these two types of tumours and the difficulties of their differential diagnosis.
CASE PRESENTATION
Our histopathological analyses uncovered a metastasising tumour with features of ameloblastic carcinoma, which developed from the ameloblastoma. We profiled the gene expression of Wnt pathway members in ameloblastoma sample of this patient, because multiple molecules of this pathway are involved in the establishing of cell polarity, cell migration or for epithelial-mesenchymal transition during tumour metastasis to evaluate features of tumor behaviour. Indeed, we found upregulation of several cell migration-related genes in our patient. Moreover, we uncovered somatic mutation BRAF p.V600E with known pathological role in cancerogenesis and germline heterozygous FANCA p.S858R mutation, whose interpretation in this context has not been discussed yet.
CONCLUSIONS
In conclusion, we have uncovered a unique case of ameloblastic carcinoma associated with an alteration of Wnt signalling and the presence of BRAF mutation. Development of harmful state of our patient might be also supported by the germline mutation in one FANCA allele, however this has to be confirmed by further analyses.
Topics: Male; Humans; Ameloblastoma; Proto-Oncogene Proteins B-raf; Odontogenic Tumors; Mutation; Carcinoma
PubMed: 37573343
DOI: 10.1186/s12903-023-03259-6 -
Medicina Oral, Patologia Oral Y Cirugia... Mar 2021Desmoplastic Ameloblastoma (DA) is a rare, true neoplasm of jaws with reported incidence of 4-13% among other variants of Ameloblastoma, however this appears distinct... (Review)
Review
BACKGROUND
Desmoplastic Ameloblastoma (DA) is a rare, true neoplasm of jaws with reported incidence of 4-13% among other variants of Ameloblastoma, however this appears distinct than the classic Ameloblastoma in anatomical distribution and clinical presentation. This is often mistaken as a fibro-osseous lesion because of its similar radiological appearance.
MATERIAL AND METHODS
To describe the clinical, radiographic and histopathological characteristics through a series of new cases of histologically proven DA including a case of an exceptionally large, recurrent lesion along with retrospective analysis of cases from literature available for an improved understanding of the behaviour and prognosis of DA. A total of 50 cases were analysed for the anatomical distribution, radiographic presentation and management. Out of the 50 cases, 47 cases were from the English literature reported from 2011 to 2019 and 3 were new cases.
RESULTS
DA showed a slight male predilection (male: female=1.17:1) with a predominance in the fourth and fifth decade of life. Mandibular involvement (52%) was more commonly seen with a marked tendency for the anterior region. Radiographically, most of the lesions presented mixed radiopacity with radiolucency(80%) and root displacement was observed in only 70.27 % cases. Recurrence rate of 26 .47 % was observed. Cases treated with resection resulted in lesser recurrence as compared to those treated with enucleation and curettage.
CONCLUSIONS
DA is distinguished by a peculiar display of clinicalopathological parameters. DA has tendency of local disposition and propensity of recurrence, which thus necessitates its aggressive management. It is not possible to conclude or report on the aggressive/recurrent nature and appropriate treatment modality for DA due to inadequate follow-up results.
Topics: Ameloblastoma; Female; Humans; Male; Mandible; Mandibular Neoplasms; Neoplasm Recurrence, Local; Radiography; Retrospective Studies
PubMed: 33037797
DOI: 10.4317/medoral.24152