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Frontiers in Oral Health 2021DNA methyltransferases (DNMTs) and the histone modification H3K9ac are epigenetic markers. This study aimed to describe the immunohistochemical expression of DNMT1,...
DNA methyltransferases (DNMTs) and the histone modification H3K9ac are epigenetic markers. This study aimed to describe the immunohistochemical expression of DNMT1, DNMT3A, DNMT3B, and H3K9ac in the dental follicle (DF), ameloblastoma (AME), and ameloblastic carcinoma (AC), correlating these expressions with the recurrence and aggressive behavior in ameloblastoma. Immunohistochemical reactions were performed in 10 human DFs, 38 ameloblastomas, and 6 AC samples. Another 59 ameloblastomas assembled in a tissue microarray were used to compare the immunoexpression with the clinical, radiographic, and histopathological characteristics and the presence of BRAFv600e mutation. Each slide was digitized as a high-resolution image and quantified by Aperio ScanScope Nuclear V9 software. All statistical analyzes were performed using GraphPad Prism statistical software. DNMT3B expression was higher in ameloblastomas than in the DFs, while the AC overexpressed all proteins. The ameloblastomas with BRAFv600e mutation, vestibular/lingual, or vestibular/palatine bone cortical disruption and maxilla involvement showed DNMT1 overexpression, while recurrent cases had high DNMT3B levels. DNA methylation and histone modification might play a role in the development, clinical aggressiveness, and recurrence rates of ameloblastoma, such as the progression to AC. Further investigation about gene methylations in ameloblastomas is needed to better understand its relationship with aggressiveness and recurrence.
PubMed: 35048062
DOI: 10.3389/froh.2021.751162 -
The Molecular Pathology of Odontogenic Tumors: Expanding the Spectrum of MAPK Pathway Driven Tumors.Frontiers in Oral Health 2021Odontogenic tumors comprise a heterogeneous group of lesions that arise from the odontogenic apparatus and their remnants. Although the etiopathogenesis of most... (Review)
Review
Odontogenic tumors comprise a heterogeneous group of lesions that arise from the odontogenic apparatus and their remnants. Although the etiopathogenesis of most odontogenic tumors remains unclear, there have been some advances, recently, in the understanding of the genetic basis of specific odontogenic tumors. The mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK) pathway is intimately involved in the regulation of important cellular functions, and it is commonly deregulated in several human neoplasms. Molecular analysis performed by different techniques, including direct sequencing, next-generation sequencing, and allele-specific qPCR, have uncovered mutations in genes related to the oncogenic MAPK/ERK signaling pathway in odontogenic tumors. Genetic mutations in this pathway genes have been reported in epithelial and mixed odontogenic tumors, in addition to odontogenic carcinomas and sarcomas. Notably, B-Raf proto-oncogene serine/threonine kinase and KRAS proto-oncogene GTPase pathogenic mutations have been reported in a high proportion of ameloblastomas and adenomatoid odontogenic tumors, respectively. In line with the reports about other neoplasms that harbor a malignant counterpart, the frequency of p.V600E mutation is higher in ameloblastoma (64% in conventional, 81% in unicystic, and 63% in peripheral) than in ameloblastic carcinoma (35%). The objective of this study was to review MAPK/ERK genetic mutations in benign and malignant odontogenic tumors. Additionally, such genetic alterations were discussed in the context of tumorigenesis, clinical behavior, classification, and future perspectives regarding therapeutic approaches.
PubMed: 35048058
DOI: 10.3389/froh.2021.740788 -
Journal of Veterinary Diagnostic... May 2022Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for... (Review)
Review
Ameloblastic carcinoma is a malignant odontogenic neoplasm that has been reported only rarely in veterinary species. A 16-y-old Arabian crossbred mare was presented for evaluation of a hard mass on the body of the mandible, with evidence of osteolysis on radiographs. Incisional biopsies revealed an invasive neoplasm comprised of spindloid epithelial cells with a high mitotic count and partial dual cytokeratin-vimentin immunoreactivity. The horse was euthanized because of rapid tumor progression 3 mo after presentation. Postmortem evaluation revealed partial obliteration of the mandible by a large, firm-to-hard, tan, locally destructive and invasive mass with no gross or histologic evidence of metastasis. Postmortem histology revealed a poorly differentiated epithelial neoplasm with variably prominent features suggestive of odontogenic histogenesis: a plexiform ribbon architecture, infrequent basilar palisading with antibasilar nuclei, rare basilar cytoplasmic clearing, subepithelial matrix hyalinization, and partial dual cytokeratin-vimentin immunoreactivity. Features of malignancy included regions of necrosis, pronounced cellular atypia, a high mitotic count, extensive tissue invasion and local tissue destruction, and extension of neoplastic cells beyond the margins of the mandibular bone. Collectively, these features are most consistent with mandibular ameloblastic carcinoma. Including our case described here, ameloblastic carcinoma has been reported in only 5 horses. The microscopic features reported most consistently are dual cytokeratin-vimentin immunoreactivity, a high mitotic count, and basilar palisading. Ameloblastic carcinoma should be considered as a differential diagnosis for rapidly growing, locally invasive masses arising from the dentate jaw of horses.
Topics: Ameloblastoma; Animals; Carcinoma; Female; Horse Diseases; Horses; Keratins; Mandibular Neoplasms; Odontogenic Tumors; Vimentin
PubMed: 35037545
DOI: 10.1177/10406387211068459 -
Frontiers in Oncology 2021The reconstruction of complex midface defects is a challenging clinical scenario considering the high anatomical, functional, and aesthetic requirements. In this study,...
The reconstruction of complex midface defects is a challenging clinical scenario considering the high anatomical, functional, and aesthetic requirements. In this study, we proposed a surgical treatment to achieve improved oral rehabilitation and anatomical and functional reconstruction of a complex defect of the maxilla with a vascularized, engineered composite graft. The patient was a 39-year-old female, postoperative after left hemimaxillectomy for ameloblastic carcinoma in 2010 and tumor-free at the 5-year oncological follow-up. The left hemimaxillary defect was restored in a two-step approach. First, a composite graft was ectopically engineered using autologous stromal vascular fraction (SVF) cells seeded on an allogenic devitalized bone matrix. The resulting construct was further loaded with bone morphogenic protein-2 (BMP-2), wrapped within the latissimus dorsi muscle, and pedicled with an arteriovenous (AV) bundle. Subsequently, the prefabricated graft was orthotopically transferred into the defect site and revascularized through microvascular surgical techniques. The prefabricated graft contained vascularized bone tissue embedded within muscular tissue. Despite unexpected resorption, its orthotopic transfer enabled restoration of the orbital floor, separation of the oral and nasal cavities, and midface symmetry and allowed the patient to return to normal diet as well as to restore normal speech and swallowing function. These results remained stable for the entire follow-up period of 2 years. This clinical case demonstrates the safety and the feasibility of composite graft engineering for the treatment of complex maxillary defects. As compared to the current gold standard of autologous tissue transfer, this patient's benefits included decreased donor site morbidity and improved oral rehabilitation. Bone resorption of the construct at the ectopic prefabrication site still needs to be further addressed to preserve the designed graft size and shape.
PubMed: 34938659
DOI: 10.3389/fonc.2021.775136 -
BMJ Case Reports Dec 2021Ameloblastic carcinoma is a rare malignant odontogenic neoplasm that exhibits diverse clinical and radiological presentations. In fact there are several differential...
Ameloblastic carcinoma is a rare malignant odontogenic neoplasm that exhibits diverse clinical and radiological presentations. In fact there are several differential diagnoses during histopathological evaluation too. Lack of adequate reports could not establish the predominant demographic, clinical and radiological presentations. For the same reasons, the role of adjuvant radiotherapy and chemotherapy is also unsubstantiated yet. This case discusses the innocuous clinical and radiological presentation of ameloblastic carcinoma in a 55-year-old man where the diagnostic confirmation was achieved through histopathological evaluation. The differential diagnoses, treatment and follow-up details of this case are discussed in light of the previous published case reports and systematic reviews of case reports in an attempt to increase the sensitisation among dentists towards ameloblastic carcinoma.
Topics: Ameloblastoma; Carcinoma; Diagnosis, Differential; Humans; Male; Mandibular Neoplasms; Middle Aged; Odontogenic Tumors
PubMed: 34906959
DOI: 10.1136/bcr-2021-246907 -
Journal of Oral and Maxillofacial... 2021Ameloblastic carcinoma (AC) is a rare malignant epithelial proliferation that is associated with an ameloblastoma or histologically resembles an ameloblastoma. It is...
Ameloblastic carcinoma (AC) is a rare malignant epithelial proliferation that is associated with an ameloblastoma or histologically resembles an ameloblastoma. It is considered to be an aggressive neoplasm that is locally invasive and spread to regional lymph nodes or distant sites. It requires aggressive surgical treatment, and regular follow-up, therefore, differs from ameloblastoma. Sometimes, ameloblastomas exhibit a mild-to-moderate degree of cytological atypia; hence, in such cases, a correlation should be established between the clinical, radiological and histopathological findings, thus detecting the aggressiveness of the tumor. Here, we present the case report of a 52-year-old male patient diagnosed as AC based on histopathological and immunohistochemical findings.
PubMed: 34349428
DOI: 10.4103/jomfp.JOMFP_71_20 -
International Journal of Environmental... Apr 2021Ameloblastic carcinoma is a rare malignant odontogenic neoplasm with a poor prognosis. It can arise de novo or from a pre-existing ameloblastoma. Research into stemness...
Ameloblastic carcinoma is a rare malignant odontogenic neoplasm with a poor prognosis. It can arise de novo or from a pre-existing ameloblastoma. Research into stemness marker expression in ameloblastic tumours is lacking. This study aimed to explore the immunohistochemical expression of stemness markers nestin, CD138, and alpha-smooth muscle actin (alpha-SMA) for the characterisation of ameloblastic tumours. Six cases of ameloblastoma and four cases of ameloblastic carcinoma were assessed, including one case of ameloblastic carcinoma arising from desmoplastic ameloblastoma. In all tumour samples, CD138 was positive, whilst alpha-SMA was negative. Nestin was negative in all but one tumour sample. Conversely, the presence or absence of these markers varied in stroma samples. Nestin was observed in one ameloblastic carcinoma stroma sample, whilst CD138 was positive in one ameloblastoma case, one desmoplastic ameloblastoma case, and in two ameloblastic carcinoma stroma samples. Finally, alpha-SMA was found positive only in the desmoplastic ameloblastoma stroma sample. Our results suggest nestin expression to be an indicator for ameloblastic carcinoma, and CD138 and alpha-SMA to be promising biomarkers for the malignant transformation of ameloblastoma. Our data showed that nestin, CD138, and alpha-SMA are novel biomarkers for a better understanding of the origins and behaviour of ameloblastic tumours.
Topics: Actins; Ameloblastoma; Biomarkers; Humans; Mandibular Neoplasms; Nestin
PubMed: 33917771
DOI: 10.3390/ijerph18083899 -
Journal of Zoo and Wildlife Medicine :... Apr 2021Giraffes () are commonly managed in zoos and conservation programs worldwide, but the current understanding of the occurrence and progression of neoplastic disease in...
Giraffes () are commonly managed in zoos and conservation programs worldwide, but the current understanding of the occurrence and progression of neoplastic disease in this species is limited by the scarcity of published reports. This study collated documented cases of neoplasia on the basis of gross and histologic evaluation of ante- and postmortem samples. In total, 30 giraffes from 22 institutions across the United States were included. Subspecies was not reported in all cases, but those identified included Masai (), Rothschild (), and reticulated subspecies (). Thirteen animals died natural deaths, 15 were euthanized, and 2 were alive at the time of this article. A total of 38 tumors were reported and classified as 18 different diagnoses, including leiomyoma (7), adenoma (4), luteoma (4), lymphoma (4), pheochromocytoma (3), squamous cell carcinoma (3), adenocarcinoma (2), ameloblastic fibroma (1), carcinomatosis of undetermined cell lineage (1), cavernous hemangioma (1), cystic granulosa cell tumor (1), dysgerminoma (1), fibrosarcoma (1), leukemia (1), lipoma (1), pituitary nerve sheath tumor (1), rhabdomyosarcoma (1), and teratoma (1). Multiple concurrent neoplastic lesions were documented in six cases. Mesenchymal tumors (18) were the majority of neoplasms. The most prevalent location, regardless of tumor type, was the female reproductive tract (14). Twenty-four neoplastic lesions were incidental findings at necropsy, whereas eight neoplasms were considered to be the primary cause of death. The findings reported here identify multiple neoplastic lesions in giraffes and could provide insight to the future management of this species.
Topics: Animals; Animals, Zoo; Female; Giraffes; Male; Neoplasms; Retrospective Studies; United States
PubMed: 33827195
DOI: 10.1638/2020-0100 -
The Pan African Medical Journal 2021head and neck cancers have essentially been a disease of the elderly but recent studies are beginning to demonstrate their increasing incidence in young people with...
INTRODUCTION
head and neck cancers have essentially been a disease of the elderly but recent studies are beginning to demonstrate their increasing incidence in young people with infections such as human papilloma virus (HPV). This study was carried out to determine the prevalence of high risk Human papilloma virus (hrHPV) related oropharyngeal carcinoma and its prevalent genotypes as well as their strength of association with HIV in adult Nigerian subjects.
METHODS
this was a cross-sectional study of 41 patients with oropharyngeal carcinomas seen over a 2-year period. Patients had incisional and/or excisional biopsy done under anesthesia. A portion of the specimen from which the DNA was extracted was placed in Digene HC2 DNA collection device while the 2 portion for histopathological analysis was fixed using 10% Neutral Buffered Formalin (NBF) and embedded in paraffin blocks. Oropharyngeal cancer HPV genotyping was done using HPV genotypes 14 real-tm quant kit (SACACE, Italy). The data was analyzed using SPSS version 23.
RESULTS
prevalence of HPV was 17.1% with a male to female ratio of 2.7: 1. The identified genotypes were 16, 33, 35 and 52 with 28.6% of patients having more than one genotype. Most of the age groups studied were affected. Squamous cell carcinoma and ameloblastic carcinoma were the cancers associated with HPV. HPV was not identified in the HIV positive patients.
CONCLUSION
high-risk human papilloma virus genotypes 16, 33, 35 and 52 are associated with oropharyngeal carcinoma in Nigeria but were not found in HIV patients. This finding provides a strong evidence for the use of the 9-valent prophylactic vaccine for the prevention of oropharyngeal cancer in Nigeria. Public awareness and HPV prevention strategies should reduce significantly the incidence of oropharyngeal carcinomas in our environment.
Topics: Adult; Aged; Ameloblastoma; Carcinoma, Squamous Cell; Cross-Sectional Studies; DNA, Viral; Female; Genotype; HIV Infections; Head and Neck Neoplasms; Humans; Male; Middle Aged; Nigeria; Oropharyngeal Neoplasms; Papillomaviridae; Papillomavirus Infections; Prevalence; Young Adult
PubMed: 33777308
DOI: 10.11604/pamj.2021.38.40.27309 -
BMC Oral Health Mar 2021Malignant odontogenic tumours are extremely rare tumours occurring within the jaws. Our study was performed to determine the demographic and clinico-pathological...
BACKGROUND
Malignant odontogenic tumours are extremely rare tumours occurring within the jaws. Our study was performed to determine the demographic and clinico-pathological features of malignant odontogenic tumours amongst a multi-ethnic Asian population.
METHODS
This was a retrospective cross-sectional study of malignant odontogenic tumours diagnosed at the Institute for Medical Research, Malaysia, from 2009 to 2019. All cases were independently reviewed and reclassified following the criteria set out in the latest edition of the World Health Organization 2017 reference text. Demographic and clinico-pathological data were recorded for each case.
RESULTS
Twenty-four cases of malignant odontogenic tumours were identified. The patients' age ranged from 16 to 79 years with the mean age at diagnosis being 50.8 years (SD = 16.18). There was a male predominance (66.7%) in this cohort of patients. The ethnic distribution appeared to reflect the Malaysian population with most cases seen amongst the Malay ethnic group (66.7%). Ameloblastic carcinoma was the most frequently diagnosed malignant odontogenic tumour (45.8%) and was also predominantly seen in males (90.9%). All patients with clear cell odontogenic carcinoma were females. There was no obvious sex predilection in primary odontogenic carcinoma not otherwise specified (NOS). The mandible (79.2%) was more frequently involved compared to the maxilla.
CONCLUSIONS
Diagnosis and management of malignant odontogenic tumours are challenging due to the rarity of these tumours. Our study has elucidated the clinico-pathological features of malignant odontogenic tumours seen in a multi-ethnic Asian population.
Topics: Adolescent; Adult; Aged; Cross-Sectional Studies; Female; Humans; Malaysia; Male; Middle Aged; Odontogenic Tumors; Referral and Consultation; Retrospective Studies; Young Adult
PubMed: 33736630
DOI: 10.1186/s12903-020-01365-3