Targeted therapies in ameloblastomas and amelobastic carcinoma-A systematic review.

Targeted therapy has the potential to be used in the neoadjuvant setting for odontogenic tumors, reducing the morbidities associated with major surgery. In this regard, the aim of this study was to summarize the current evidence on the different forms of targeted therapy, effectiveness, and drawbacks of this course of treatment. Four databases were searched electronically without regard to publication date or language. Grey literature searches and manual searches were also undertaken. Publications with sufficient clinical data on targeted therapy for odontogenic tumors were required to meet the criteria for eligibility. The analysis of the data was descriptive. A total of 15 papers comprising 17 cases (15 ameloblastomas and 2 ameloblastic carcinomas) were included. Numerous mutations were found, with BRAF V600E being most common. Dabrafenib was the most utilized drug in targeted therapy. Except for one case, the treatment reduced the size of the lesion (16/17 cases), showing promise. Most of the adverse events recorded were mild, such as skin issues, voice changes, abnormal hair texture, dry eyes, and systemic symptoms (e.g., fatigue, joint pain, and nausea). It is possible to reach the conclusion that targeted therapy for ameloblastoma and ameloblastic carcinoma may be a useful treatment strategy, based on the findings of the included studies.

Calibration improves the agreement in grading oral epithelial dysplasia-Findings from a National Workshop in Malaysia.

INTRODUCTION: A major pitfall of many of the established oral epithelial dysplasia (OED) grading criteria is their lack of reproducibility and accuracy to predict malignant transformation. The main objective of this study was to determine whether calibration of practicing oral pathologists on OED grading could improve the reproducibility of the WHO 2017 and the binary OED grading systems. METHODS: A nationwide online exercise was carried out to determine the influence of calibration on the reproducibility of the WHO 2017 and the binary OED grading systems. RESULTS: A significant improvement was observed in the inter-observer agreement for the WHO 2017 OED grading system (K 0.196 vs. 0.448; Kw 0.357 vs. 0.562) after the calibration exercise. The significant difference (p = 0.027) in the level of agreement between those with five or more years and less than 5 years of experience was no more observed (p = 0.426) after the calibration exercise. The percent agreement for binary grading was significantly higher (91.8%) for buccal mucosal lesions as compared to lesions on the tongue after the calibration exercise. CONCLUSION: This study validates the significance of calibration in improving the reproducibility of OED grading. The nationwide exercise resulted in a statistically significant improvement in the inter-observer agreement for the WHO 2017 OED grading system among a large number of oral pathologists. It is highly recommended that similar exercises should be organized periodically by professional bodies responsible for continuing education among oral pathologists to improve the reliability of OED grading for optimal treatment of oral potentially malignant disorders.

Salivary biomarkers: Effective diagnostic tool for oral leukoplakia and oral squamous cell carcinoma.

OBJECTIVE: To identify potential salivary biomarkers for the diagnosis and monitoring of disease progression in oral squamous cell carcinoma and oral leukoplakia. MATERIALS AND METHODS: An advance search from PubMed and Hindawi was performed with keywords; oral leukoplakia/oral squamous cell carcinoma, salivary biomarker and diagnosis/prognosis. An additional search of articles was done through a manual search from the Google Scholar database. RESULTS: Twenty studies involving salivary biomarkers as diagnostic tools for oral squamous cell carcinoma and/or oral leukoplakia were identified. A narrative review was carried out. CONCLUSION: Single or multiple salivary biomarkers reported by most studies have shown great potential as diagnostic tools for oral squamous cell carcinoma and oral leukoplakia. However, the validation of sensitivity and specificity should be carried out to ensure the accuracy of the biomarkers. Furthermore, a standardised method for saliva collection should be established to prevent variability in the expression of biomarkers.

EBV-Associated Smooth Muscle Tumor in the Malar Area of an HIV-Positive Patient: A Case Report.

BACKGROUND: EBV-associated smooth muscle tumors (EBV-SMTs) are rare and typically develop in individuals with a compromised immune system, particularly those who have acquired immunodeficiency syndrome (AIDS) or who have undergone organ transplants. METHODS: We document a case of EBV-SMT in an HIV-positive 25-year-old man. The lesion was incised and assessed histologically and a panel of immune markers were performed. EBV association was demonstrated by in situ hybridization for EBV-encoded RNA (EBER-ISH). RESULTS: Microscopically, the tumor composed of mildly pleomorphic, ovoid to spindled cells with numerous slit-like vascular channels. The tumor cells exhibited diffuse and strong immunoreactivity for smooth muscle actin (SMA) and focal positivity for h-caldesmon. EBER-ISH of the tumor cells revealed strong positive nuclear signals. CONCLUSION: The histopathological features of EBV-SMT do not conform to either benign or malignant SMTs and it has a peculiar predilection to develop at sites unusual for leiomyoma or leiomyosarcoma. The key diagnostic features of EBV-SMT include history of immunosuppression, histologic evidence of primitive and mildly pleomorphic cells maintaining blunt nuclear features in most areas, and positivity for EBER-ISH.

Odontogenic Carcinosarcoma: An Updated Literature Review and Report of a Case.

BACKGROUND: Odontogenic carcinosarcoma (OCS) is an exceptionally rare malignant mixed odontogenic neoplasm, which mostly arises from recurrent benign odontogenic tumour that undergoes malignant transformation. METHODS: A literature review was conducted using the keyword of "Odontogenic carcinosarcoma" and all relevant articles were screened. The data collected include demographic profile (age, gender), clinical information (symptoms, location, size), radiologic features, histopathological examination, management, recurrence, metastases, and survival status. RESULTS: A total of 17 OCS cases including a new case from our hospital. The incidence of OCS was highest in the third decades of life with predilection for male and posterior region of mandible. Clinically, patients may present with swelling and neurological symptoms. Radiographic examination often showed radiolucency with ill-defined border. This tumour demonstrates an aggressive behaviour with reported cases of distant metastases to the lung, lymph nodes, rib, and pelvis. Here, we report an interesting case of OCS in a 38-year-old man with a previous diagnosis of ameloblastoma. The patient was diagnosed with ameloblastoma but refused surgical intervention and returned after 10 years with rapidly enlarging mass on the right side of mandible. Microscopically, the lesion appears as biphasic odontogenic tumour with malignant cytological features seen in both epithelium and mesenchymal components. The spindle to round mesenchymal tumour cells were only positive for vimentin. Ki67 proliferation index was high in both epithelium and mesenchymal components. CONCLUSION: This case showed the tendency of untreated ameloblastoma to undergo malignant changes in the long term.

Controversies in verruco papillary lesions of the oral cavity-A systematic review.

INTRODUCTION: Verruco papillary lesions (VPL) in the oral cavity encompass a spectrum of lesions starting from benign, potentially malignant to entirely malignant tumors. Much of the controversies in these entities occur due to lack of consensus on the disease characteristics and the management. This systematic review was conducted to identify and describe different lesions categorized as VPL in the oral cavity and their association with malignancy. METHODS: An electronic literature search was conducted in MEDLINE (via PubMed), Scopus, LILAC, IMSEAR, and CENTRAL databases, which retrieved a total of 1020 abstracts. These abstracts were managed through Rayyan and Mendeley software, and only 28 studies with high quality were included in the systematic review. RESULTS: Studies were published from 1992 to 2021. From the extracted data, nine different entities under the umbrella term VPL were identified associated with malignancy. We describe the clinical and histopathological characteristics of these and propose a uniform framework for nomenclature. CONCLUSIONS: Lack of well-planned research with adequate follow-up duration and inadequate quality standards are major barriers for the lack of evidence. The use of uniform nomenclature, as proposed in this study, and research at the molecular level will greatly reduce the controversies in understanding oral VPL associated with malignancy.

Image collection and annotation platforms to establish a multi-source database of oral lesions.

OBJECTIVE: To describe the development of a platform for image collection and annotation that resulted in a multi-sourced international image dataset of oral lesions to facilitate the development of automated lesion classification algorithms. MATERIALS AND METHODS: We developed a web-interface, hosted on a web server to collect oral lesions images from international partners. Further, we developed a customised annotation tool, also a web-interface for systematic annotation of images to build a rich clinically labelled dataset. We evaluated the sensitivities comparing referral decisions through the annotation process with the clinical diagnosis of the lesions. RESULTS: The image repository hosts 2474 images of oral lesions consisting of oral cancer, oral potentially malignant disorders and other oral lesions that were collected through MeMoSA® UPLOAD. Eight-hundred images were annotated by seven oral medicine specialists on MeMoSA® ANNOTATE, to mark the lesion and to collect clinical labels. The sensitivity in referral decision for all lesions that required a referral for cancer management/surveillance was moderate to high depending on the type of lesion (64.3%-100%). CONCLUSION: This is the first description of a database with clinically labelled oral lesions. This database could accelerate the improvement of AI algorithms that can promote the early detection of high-risk oral lesions.

Clinical and demographic characteristics of adenomatoid odontogenic tumors: analysis of 116 new cases from a single center / Características clínicas e demográficas de tumores odontogênicos adenomatoides: análise de 116 novos casos em um único centro

Abstract Introduction The adenomatoid odontogenic tumor is a relatively uncommon odontogenic neoplasm representing about 4.7% of all odontogenic tumors. Objective The aim of this study was to determine the demographic and clinical profile of the adenomatoid odontogenic tumors in a Sri Lankan population. Methods Data gathered from the cases received for a period of 38 years from the Department of Oral Pathology, Faculty of Dental Sciences, University of Peradeniya. Request forms, biopsy reports and electronic data base of the department were used to obtain relevant information. Demographic data including age, gender and location of the tumor were included in the analysis. Results Out of 116 cases of adenomatoid odontogenic tumor, the mean age was 21.02 ± 11.24. It occurs more fre quently in the second decade of life, more prevalent in females, most often associated with the maxilla, predominantly affecting anterior jaw bones and presenting mostly in the right side of the jaw bone. The results from the present study showed the statistically significant relationship with site of occurrence (maxilla/mandible) and age (p< 0.005). Further, depending on whether it occurs in anterior/mid/posterior site also showed a significant relationship with age (p≤ 0.001). However, side of occurrence, left or right or site of occurrence, showed no statistically significance with age (p> 0.05). Conclusion Adenomatoid odontogenic tumor occurs more frequently in the second decade of life with a significant female predominance and the commonest site is anterior maxilla. This study revealed few differences on demographic and clinical presentations of adenomatoid odontogenic tumor from some regions of the world.

Resumo Introdução O tumor odontogênico adenomatoide é uma neoplasia odontogênica relativamente incomum que representa cerca de 4,7% de todos os tumores odontogênicos. Objetivo Determinar o perfil demográfico e clínico dos tumores odontogênicos adenomatoides em uma população do Sri Lanka. Método Os dados foram obtidos dos casos tratados por 38 anos no Departamento de Patologia Oral da Faculty of Dental Sciences, University of Peradeniya. Formulários de solicitação, relatórios de biópsia e o banco de dados eletrônico do departamento foram usados para obter informações relevantes. Dados demográficos, idade, sexo e localização do tumor foram incluídos na análise. Resultados Dos 116 casos de tumor odontogênico adenomatoide, a média de idade foi de 21,02 ± 11,24. Ocorreu com mais frequência na segunda década de vida, e foi mais prevalente no sexo feminino, mais frequentemente associado à maxila, afetou predominantemente os ossos da mandíbula anterior e apresentou-se principalmente no lado direito dos ossos da mandíbula. Os resultados do presente estudo mostraram uma relação estatisticamente significante com o local da ocorrência (maxila/mandíbula) e idade (p < 0,005). Além disso, de acordo com o local de ocorrência, região anterior/média/posterior, também apresentou relação significante com a idade (p ≤ 0,001). Entretanto, nem o lado acometido, direito ou esquerdo, ou o sítio de ocorrência foi estatisticamente significante em relação à idade (p > 0,05). Conclusão O tumor odontogênico adenomatoide ocorre com mais frequência na segunda década de vida, com predominância feminina significativa, e o local mais comum é a maxila anterior. Este estudo revelou poucas diferenças nas apresentações demográficas e clínicas do tumor odontogênico adenomatoide de algumas regiões do mundo.

Sclerosing odontogenic carcinoma — review of all published cases: is it a justifiable addition as a malignancy? / Carcinoma odontogênico esclerosante - revisão de todos os casos publicados: sua classificação como tumor maligno é justificável?

Abstract Introduction Sclerosing odontogenic carcinoma was a new addition to the list of head and neck tumors by World Health Organization in 2017. This lesion has scarcely been reported and a lack of pathognomonic markers for diagnosis exists. Objective The aim of the study was to summarize findings from the available literature to provide up-to-date information on sclerosing odontogenic carcinoma and to analyse clinical, radiological, and histopathological features to obtain information for and against as an odontogenic malignancy. Methods We conducted a comprehensive review of literature by searching Pubmed, EBSCO and Web of Science databases, according to PRISMA guidelines. All the cases reported as sclerosing odontogenic carcinoma in English were included. Data retrieved from the articles were gender, age, clinical features, site, relevant medical history, radiographical findings, histopathological findings, immunohistochemical findings, treatments provided and prognosis. Results Mean age at diagnosis of sclerosing odontogenic carcinoma was 54.4 years with a very slight female predilection. Sclerosing odontogenic carcinoma was commonly reported in the mandible as an expansile swelling which can be asymptomatic or associated with pain or paraesthesia. They appeared radiolucent with cortical resorption in radiograph evaluation. Histologically, sclerosing odontogenic carcinoma was composed of epithelioid cells in dense, fibrous, or sclerotic stroma with equivocal perineural invasion. Mild cellular atypia and inconspicuous mitotic activity were observed. There is no specific immunohistochemical marker for sclerosing odontogenic carcinoma. AE1/AE3, CK 5/6, CK 14, CK19, p63 and E-cadherin were the widely expressed markers for sclerosing odontogenic carcinoma. Surgical resection was the main treatment provided with no recurrence in most cases. No cases of metastasis were reported. Conclusion From the literature available, sclerosing odontogenic carcinoma is justifiable as a malignant tumor with no or unknown metastatic potential which can be adequately treated with surgical resection. However, there is insufficient evidence for histological grading or degree of malignancy of this tumor.

Resumo Introdução O carcinoma odontogênico esclerosante é a nova adição à lista de tumores de cabeça e pescoço da Organização Mundial da Saúde em 2017. Essa lesão é pouco relatada e não há marcadores patognomônicos para o diagnóstico. Objetivo Resumir os achados da literatura disponível para fornecer informações atualizadas sobre o carcinoma odontogênico esclerosante e analisar as características clínicas, radiológicas e histopatológicas a favor e contra sua classificação como uma lesão odontogênica maligna. Método Uma revisão abrangente da literatura foi feita nos bancos de dados Pubmed, Ebsco e Web of Science, de acordo com as diretrizes do Prisma. Todos os casos relatados em inglês como carcinoma odontogênico esclerosante foram incluídos. Os dados recuperados dos artigos foram sexo, idade, características clínicas, sítio do tumor, histórico médico relevante, achados radiográficos, achados histopatológicos, achados imuno-histoquímico, tratamentos instituídos e prognóstico. Resultados A média de idade ao diagnóstico de carcinoma odontogênico esclerosante foi de 54,4 anos, com uma predileção muito leve pelo sexo feminino. Tumores do tipo carcinoma odontogênico esclerosante foram comumente relatados na mandíbula como um edema expansivo, que pode ser assintomático ou associado a dor ou parestesia. Eles têm aparência radiolucente com reabsorção cortical na radiografia. Histologicamente, o carcinoma odontogênico esclerosante é composto por células epitelioides em estroma denso, fibroso ou esclerótico com invasão perineural ambígua. Atipia celular leve e atividade mitótica imperceptível foram observadas. Não há um marcador imuno-histoquímico específico para SOC. AE1/AE3, CK 5/6, CK 14, CK19, p63 e E-caderina foram os marcadores amplamente expressos para carcinoma odontogênico esclerosante. A ressecção foi o principal tratamento feito sem recorrência na maioria dos casos. Nenhum caso de metástase foi relatado. Conclusão De acordo com a literatura disponível, é justificável classificar o carcinoma odontogênico esclerosante como um tumor maligno com nenhum ou desconhecido potencial metastático, que pode ser tratado adequadamente com ressecção cirúrgica. Entretanto, não há evidências suficientes para a graduação histológica ou de malignidade desse tumor.

Clinical and demographic characteristics of adenomatoid odontogenic tumors: analysis of 116 new cases from a single center.

INTRODUCTION: The adenomatoid odontogenic tumor is a relatively uncommon odontogenic neoplasm representing about 4.7% of all odontogenic tumors. OBJECTIVE: The aim of this study was to determine the demographic and clinical profile of the adenomatoid odontogenic tumors in a Sri Lankan population. METHODS: Data gathered from the cases received for a period of 38 years from the Department of Oral Pathology, Faculty of Dental Sciences, University of Peradeniya. Request forms, biopsy reports and electronic data base of the department were used to obtain relevant information. Demographic data including age, gender and location of the tumor were included in the analysis. RESULTS: Out of 116 cases of adenomatoid odontogenic tumor, the mean age was 21.02 ±â€¯11.24. It occurs more fre quently in the second decade of life, more prevalent in females, most often associated with the maxilla, predominantly affecting anterior jaw bones and presenting mostly in the right side of the jaw bone. The results from the present study showed the statistically significant relationship with site of occurrence (maxilla/mandible) and age (p < 0.005). Further, depending on whether it occurs in anterior/mid/posterior site also showed a significant relationship with age (p ≤ 0.001). However, side of occurrence, left or right or site of occurrence, showed no statistically significance with age (p > 0.05). CONCLUSION: Adenomatoid odontogenic tumor occurs more frequently in the second decade of life with a significant female predominance and the commonest site is anterior maxilla. This study revealed few differences on demographic and clinical presentations of adenomatoid odontogenic tumor from some regions of the world.

Sclerosing odontogenic carcinoma - review of all published cases: is it a justifiable addition as a malignancy?

INTRODUCTION: Sclerosing odontogenic carcinoma was a new addition to the list of head and neck tumors by World Health Organization in 2017. This lesion has scarcely been reported and a lack of pathognomonic markers for diagnosis exists. OBJECTIVE: The aim of the study was to summarize findings from the available literature to provide up-to-date information on sclerosing odontogenic carcinoma and to analyse clinical, radiological, and histopathological features to obtain information for and against as an odontogenic malignancy. METHODS: We conducted a comprehensive review of literature by searching Pubmed, EBSCO and Web of Science databases, according to PRISMA guidelines. All the cases reported as sclerosing odontogenic carcinoma in English were included. Data retrieved from the articles were gender, age, clinical features, site, relevant medical history, radiographical findings, histopathological findings, immunohistochemical findings, treatments provided and prognosis. RESULTS: Mean age at diagnosis of sclerosing odontogenic carcinoma was 54.4 years with a very slight female predilection. Sclerosing odontogenic carcinoma was commonly reported in the mandible as an expansile swelling which can be asymptomatic or associated with pain or paraesthesia. They appeared radiolucent with cortical resorption in radiograph evaluation. Histologically, sclerosing odontogenic carcinoma was composed of epithelioid cells in dense, fibrous, or sclerotic stroma with equivocal perineural invasion. Mild cellular atypia and inconspicuous mitotic activity were observed. There is no specific immunohistochemical marker for sclerosing odontogenic carcinoma. AE1/AE3, CK 5/6, CK 14, CK19, p63 and E-cadherin were the widely expressed markers for sclerosing odontogenic carcinoma. Surgical resection was the main treatment provided with no recurrence in most cases. No cases of metastasis were reported. CONCLUSION: From the literature available, sclerosing odontogenic carcinoma is justifiable as a malignant tumor with no or unknown metastatic potential which can be adequately treated with surgical resection. However, there is insufficient evidence for histological grading or degree of malignancy of this tumor.

Expression of Ki-67, Cornulin and ISG15 in non-involved mucosal surgical margins as predictive markers for relapse in oral squamous cell carcinoma (OSCC).

BACKGROUND: Local relapse of oral squamous cell carcinoma in non-involved mucosal surgical margins indicated possibility of field alteration in the margins, which could be predicted with certain biomarkers. The objectives were to evaluate the expression of Ki-67, Cornulin and ISG15 in non-involved mucosal surgical margins and the association of clinicopathological prognosticators with local relapse in oral squamous cell carcinoma. METHODS: Surgical margins from the study (relapse) group (n = 23), control (non-relapse) group (n = 32) and normal oral mucosa (n = 5) were immunohistochemically stained using Ki-67, Cornulin and ISG15 antibodies. Association between expression of markers and clinicopathological prognosticators with local relapse in oral squamous cell carcinoma was analyzed statistically. RESULTS: The study group surgical margins demonstrated significantly decreased Cornulin expression (p = 0.032). Low Cornulin expression was significantly associated with local relapse (p = 0.004) and non-tongue primary tumor (p = 0.013). Although not significantly associated with local relapse, expression of Ki-67 was significantly reduced in female patients (p = 0.041). Age above 57.5 years, Chinese & Indian ethnicity, alcohol consumption, epithelial dysplasia in surgical margins, and type III and IV patterns of invasion of tumor were also significantly related to local relapse. Regression analysis showed low expression of Cornulin (p = 0.018), and increased patient's age (p = 0.008) were predictors of local relapse in oral squamous cell carcinoma, with 34-fold risk and 18-fold risk, respectively. Expression of Ki-67 and ISG15 did not show significant association with local relapse in oral squamous cell carcinoma. CONCLUSION: Low expression of Cornulin is an independent predictor of relapse in oral squamous cell carcinoma.

Association of clinicopathological factors and treatment modalities in the recurrence of ameloblastoma: Analysis of 624 cases.

BACKGROUND: Ameloblastoma is an odontogenic tumour exhibiting locally invasive behaviour and high recurrence rate after treatment. Conventional ameloblastoma is reportedly been more aggressive showing infiltrative growth patterns and a tendency for recurrence. This is a retrospective study performed to analyse the relationship between clinicopathological characteristics and treatment modalities in the recurrence of ameloblastoma. METHODS: 624 cases of ameloblastoma comprising of 519 non-recurrent ameloblastoma and 105 recurrent ameloblastoma from two main diagnostic centres in Malaysia and Sri Lanka were included. The demographic data, clinical characteristics, histopathological data, treatment modality and episodes of recurrence were extracted and analysed. RESULTS: The mean age for recurrent ameloblastoma was 37.23 with a peak occurrence in the third decade of life. Recurrent ameloblastoma was marginally female predominant with male to female ratio of 1:1.3. Mandible was the commonest site for the recurrence with a predilection for more than two segments of left mandible followed by left posterior mandible. Follicular (58.1%) histopathological variant was the most reported type to recur followed by plexiform (17.1%). 49.5% of recurrent cases were treated with conservative approach. 65.7% of recurrent cases demonstrated a single episode of recurrence. Mixed (follicular and plexiform) histopathological variants showed the longest average years (11.5 years) for the single episode of recurrence. Plexiform ameloblastoma treated with conservative approach recurred in the shortest follow-up period. The recurrence of ameloblastoma was significantly associated with age group, sub-site of occurrence and histopathological variants (p<0.05). CONCLUSION: This study showed that age, sub-site of occurrence and histopathological variants are significant factors responsible for the recurrence of ameloblastoma.

Clinico-Pathological Presentations of Cystic and Classic Adenomatoid Odontogenic Tumors.

The objective of the study is to present the clinico-pathological features of cystic and classic adenomatoid odontogenic tumors (AOTs) in order to identify the differences between the two variants of AOT. MATERIALS AND METHOD: The study sample comprised of 41 AOTs, which were categorized into cystic and classic AOTs. Cystic AOTs are diagnosed as such when macroscopic and microscopic evidence of a cyst is present together with histopathological criteria of AOT (WHO-2017). RESULTS: The study sample comprised of eleven cystic and thirty classic AOTs. Eight cystic AOTs were regarded as arising from dentigerous cysts as these lesions were attached to the cemento-enamel junction of the impacted teeth. Though not statistically significant, in contrast to classic AOTs which showed female predilection, cystic AOTs were more prevalent in males. Cystic AOTs tend to present as significantly larger lesions compared to classic AOTs (p < 0.02). In both cystic and classic AOTs, duct-like structures and epithelial whorls were the two most prominent histopathological features present in the majority of tumors. Two AOTs with massive amounts of dentinoid occurred in the mandible and presented as large lesions that eroded cortical bone. None of the 12 patients with follow-up information presented with recurrences. CONCLUSION: Except for the size of the lesion, no significant clinico-pathological differences were observed between cystic and classic AOTs. Therefore the cystic AOTs can be considered as a variant of AOT with enucleation, simple excision, or radical excision as the treatment of choice depending on the extent of the lesion, similar to classic AOTs.

Unicystic ameloblastoma: Analysis of 370 cases in a single center in Sri Lanka.

BACKGROUND: Unicystic ameloblastoma (UA) is a variant of ameloblastoma that has a relatively benign biologic behavior and mostly occurs in a younger age group. The entire cystic lining of unicystic ameloblastoma may not always be uniformly characteristic and may partly consist of non-specific epithelium or dentigerous cyst-like lining. The variability seen reinforces the advice that multiple biopsies should be taken from large cystic lesions to represent the entire lesion. METHODS: All cases were retrieved from the archives of our unit from 1986 to 2016. Demographic data such as age, gender, and primary site were recorded. Histologically, all the cases were subcategorized according to the WHO 2017 classification. RESULTS: UA accounts for 31.1% out of all different subtypes of ameloblastoma, and male-to-female ratio is 1.08:1. Age ranged from 4 to 88 years with the mean age of 30.25 years. Peak incidence of UA was found in the range of 11-20 years, and 89% of them occurred in the mandible and 55.3% in the canine-to-first molar region. The right side was frequent in both upper and lower jaws. Of the total sample, 233 (63%) cases were luminal and 137 (37%) cases were mural, and 13 cases recurred (3.5%). CONCLUSION: The present report analyzes the largest UA sample in a single center. There is a clear need for further large case-controlled retrospective or prospective studies of the management of UA with careful and follow-up studies to draw conclusions on the correct method of treatment of these lesions.

Malignant transformation of a long-standing submental dermoid cyst to a carcinosarcoma: a case report.

BACKGROUND: Submental dermoid cysts are uncommon midline cysts which occur due to entrapment of ectoderm between the second and third branchial arches during embryogenesis. Most dermoid cysts of the head and neck are benign, but rarely malignant transformation may occur. To the best of our knowledge, this is the first report of a carcinosarcoma arising in a submental dermoid cyst. CASE PRESENTATION: A 42-year-old Sri Lankan Tamil man presented with a large cystic swelling in his submental region which was diagnosed as an extensive submental dermoid cyst. The cyst had been asymptomatic for 11 years but there was sudden enlargement and pain during the past 2 months. On surgical removal, a primary carcinosarcoma arising from part of the cyst wall was identified. After completion of radiotherapy, the disease was well controlled and he was disease free at 18 months. CONCLUSIONS: Although extremely rare, a dermoid cyst of the submental region can undergo malignant transformation. It can be successfully treated with surgical excision and radiotherapy.

Oral submucous fibrosis: a historical perspective and a review on etiology and pathogenesis.

Oral submucous fibrosis (OSF) is a chronic, insidious disease characterized by progressive submucosal fibrosis of the oral cavity and the oropharynx. People affected by this disease mostly live in south Asia, but migrants from these countries to the United States and Europe may present with OSF. We provide a historical background of the disease, and the objective of this review is to update the current knowledge on the etiology and etiopathogenesis of OSF.

Oral submucous fibrosis: review on mechanisms of malignant transformation.

Research studies focusing on various aspects of carcinogenesis in the background of fibrosis have advanced significantly in the recent past, allowing us to understand the mechanisms involved in malignant transformation of oral submucous fibrosis (OSF), the most prevalent potentially malignant oral disorder in South Asia. The role of areca nut as a carcinogen has been proven beyond doubt, with a large number of animal studies demonstrating its carcinogenicity, mutagenicity, and genotoxicity. Studies on the molecules implicated in cell cycle regulation, hypoxia, processes leading to DNA double-strand breaks, senescence, and many other pathways related to carcinogenesis have shown ample evidence for the malignant transformation in OSF induced by areca nut. More importantly, the understanding of the mechanisms of malignant transformation may lead to early diagnosis of oral squamous cell carcinoma arising in the background of OSF, which is now considered to constitute a clinicopathologically distinct disease, and the differences are believed to arise from the differential mechanisms of areca nut carcinogenesis. Therefore, the objective of this study is to review the literature on the various mechanisms leading to the malignant transformation of OSF.