Solitary fibrous tumour of the oral cavity: An update.

BACKGROUND: Solitary fibrous tumour is an unusual neoplasm of the oral cavity that is sometimes not clinically distinguishable from other lesions. The purpose of the present study was to review the clinical, microscopic and molecular aspects of malignant and benign solitary fibrous tumour of the oral cavity currently available in literature. METHODS: For our review, an electronic search was performed using PubMed, Scopus, Ovid/MedLine, Web of science and ProQuest Dissertations and Theses Global database. RESULTS: A total of 74 publications reporting 150 cases were included. Oral solitary fibrous tumours are most frequently described as submucosal, well-circumscribed, asymptomatic nodule, more prevalent in females in their fourth to fifth decades of life. Buccal mucosa is the most commonly affected site by the benign tumour variant, whereas the tongue is the most common location affected by the malignant form of the neoplasm. Most of the lesions were treated by conservative surgery. One recurrent malignant tumour and one metastasis are reported. CONCLUSION: Asymptomatic normal-coloured submucosal nodules located in the buccal mucosa and tongue in adult patients are suggestive of oral solitary fibrous tumour, but only a careful microscopic examination can differentiate benign from malignant variants and the use of immunohistochemistry (CD34, Bcl-2, CD99 and STAT6), and cytogenetic studies (NAB2-STAT6) contribute significantly to confirm the diagnosis of solitary fibrous tumour in difficult cases.

Epstein-Barr Virus-Positive Diffuse Large B-Cell Lymphoma, Not Otherwise Specified, in the Oral Cavity.

Lymphomas of the oral cavity are rare and the most frequent type is diffuse large B-cell lymphoma (DLBCL). Epstein-Barr virus (EBV) is known to be associated with the development of different lymphomas. In 2008, the World Health Organization provisionally included the EBV-positive DLBCL of the elderly in the classification of hematopoietic and lymphoid tumors as a lymphoma occurring in older individuals without any known immunodeficiency. However, it has since been recognized that this entity may occur in younger individuals and present similar clinical parameters in both age groups. As a result, the 2017 revision has declined the term elderly and modified it to EBV-positive DLBCL, not otherwise specified (NOS). In this report, we describe a rare case of EBV-positive DLBCL, NOS, presenting as a painless swelling in the oral cavity. This entity shows a more aggressive clinical course than EBV-negative DLBCL, and other lymphoproliferative disorders should be considered in the differential diagnosis.

Low-level laser as a complementary therapy in orofacial granulomatosis management: a case report.

Orofacial granulomatosis (OFG) is a chronic inflammatory disease that typically affects the soft tissues of the orofacial region. The most common clinical manifestation of OFG is lip swelling, which may be associated with intrabuccal ulcerations and increased growth of the gingiva and mucosa, as well as cutaneous erythema and facial edema. The treatment for OFG is challenging, and sometimes considered unsatisfactory. Thus, this study presents a case report of OFG and the therapeutic regimen applied. A 47-year-old man presented with increased lip volume which had started 10 months earlier. His lips were thick with a fibroelastic consistency, which were painless upon palpation. Incisional biopsy and histopathological analysis of the upper lip revealed non-specific granulomatous inflammation and the diagnosis of OFG was subsequently made. Low-level laser therapy was successfully used to treat OFG in this case, and appears to be an efficient treatment for OFG when corticosteroid therapy is not enough.

The importance of BRAF-V600E mutation to ameloblastoma metabolism.

BACKGROUND: Ameloblastoma is a locally infiltrative, aggressive epithelial odontogenic neoplasm. BRAF-V600E mutation is frequently found in this tumor and has a pivotal role in its pathogenesis, but the consequences of this alteration need to be addressed. An untargeted metabolomics approach was applied to verify whether metabolic disturbances are related to tumor biology and whether BRAF-V600E mutation contributes to these alterations. METHODS: Formalin-fixed and paraffin-embedded tissue specimens from thirteen ameloblastoma and six dental follicles were included in this study. BRAF mutational status was determined by competitive allele-specific real-time PCR. Metabolite extracts were analyzed using gas chromatography coupled to mass spectrometry. Univariate and multivariate statistical methods were employed to compare the metabolic profiles of the samples. RESULTS: The abundance of eleven metabolites was significantly higher in ameloblastoma in relation to dental follicles, including amino acids, fatty acids, carbohydrates, inorganic acids, and organoheterocyclic compounds. The presence of BRAF-V600E mutations in ameloblastoma was related to decreased levels of glycerol in comparison with tumors carrying only wild-type alleles of this gene. No metabolic differences were observed between recurrent and primary manifestations of ameloblastoma. CONCLUSIONS: Ameloblastoma exhibits a distinct metabolic profile from normal odontogenic epithelium. BRAF-V600E may contribute to metabolic alterations in ameloblastoma. Collectively, our findings suggest that metabolic alterations might play a role in tumor pathogenesis.

Análise do perfil metabolômico do ameloblastoma / Analysis of ameloblastoma metabolomic profile

O ameloblastoma é um tumor benigno que se origina do epitélio odontogênico. A patogênese não é completamente compreendida e envolve alterações genéticas como a mutação do gene BRAF. Uma vez que a lesão apresenta comportamento localmente infiltrativo e alta tendência a recidivas locais, o tratamento usualmente requer excisão cirúrgica total da lesão, resultando em deformidade facial, grande morbidade e, consequentemente, um impacto importante na vida do paciente acometido. A metabolômica representa o estudo do conjunto de metabólitos de um sistema biológico e fornece, assim, informações finais, mais intimamente relacionadas ao fenótipo estudado, a respeito das interações envolvendo alterações genéticas, atividade enzimática e reações metabólicas. O uso de amostras fixadas em formol e preservadas em parafina tem se mostrado conveniente em experimentos metabolômicos por representar uma fonte abundante de material biológico para pesquisa e por demonstrar confiabilidade no seu uso. Desta maneira, o objetivo desse estudo foi avaliar o perfil metabolômico do ameloblastoma e identificar vias metabólicas possivelmente envolvidas na patogênese e progressão da lesão, assim como relacionar estes achados com a presença da mutação V600E do gene BRAF. O estudo foi aprovado pelo Comitê de Ética em Pesquisa da Universidade Federal de Minas Gerais sob CAAE número 97428718.5.0000.5149. Foram utilizadas 14 amostras tumorais fixadas em formol e embebidas em parafina e 6 amostras de epitélio odontogênico morfologicamente normal obtidos de folículos dentários. Identificou-se os metabólitos através de cromatografia gasosa acoplada a espectrometria de massas e a presença da mutação BRAF-V600E foi avaliada através de PCR em tempo real. Os dados obtidos foram submetidos a análises estatísticas univariadas e multivariadas. Onze metabólitos foram encontrados significativamente mais elevados no ameloblastoma em relação aos folículos dentais, incluindo aminoácidos, ácidos graxos, carboidratos, ácidos inorgânicos e compostos organo-heterocíclicos. A presença da mutação BRAF-V600E nas amostras foi relacionada à diminuição dos níveis de glicerol em comparação com tumores portadores apenas de alelos do tipo selvagem deste gene. Não foram observadas diferenças metabólicas entre ameloblastomas recidivantes e ameloblastomas primários. Conclui-se que o ameloblastoma apresenta um perfil metabolômico diferente do tecido odontogênico morfologicamente normal e que a mutação BRAF-V600E pode contribuir para algumas alterações metabólicas presentes no ameloblastoma, o que pode estar relacionado com a patogênese deste tumor.

Ameloblastoma is a benign tumor that originates from the odontogenic epithelium. The pathogenesis is not completely understood and involves genetic alterations such as the mutation of the BRAF gene. Since the lesion presents locally infiltrative behavior and a high potential to local recurrences, the treatment usually requires total surgical excision of the lesion, resulting in facial deformity, great morbidity and, consequently, a significant impact on the life of the affected patient. The metabolomics represents the study of the metabolites set of a biological system. It provides final information more closely related to the studied phenotype regarding the interactions involving genetic alterations, enzymatic activity and metabolic reactions. The use of formalin-fixed and paraffin-embedded samples has been shown to be convenient in metabolomics experiments because it represents an abundant source of biological material for research and for demonstrating reliability in its use. Thus, the aim of this study was to evaluate the metabolic profile of ameloblastoma and to identify metabolic pathways possibly involved in the pathogenesis and progression of this lesion, as well as to corelate these findings to the presence of BRAF-V600E mutation. The study was approved by the Research Ethics Committee of the Universidade Federal de Minas Gerais under CAAE number 97428718.5.0000.5149. Fourteen formalin-fixed and paraffin-embedded tumor samples and 6 samples of morphologically normal odontogenic epithelium obtained from dental follicles were used. Metabolites were identified by gas chromatography coupled to mass spectrometry and the presence of the BRAF-V600E mutation was assessed by realtime PCR. The data was submitted to univariate and multivariate statistical analyses. Eleven metabolites were found to be significantly higher in ameloblastoma compared to dental follicles, including amino acids, fatty acids, carbohydrates, inorganic acids and organoheterocyclic compounds. The presence of the BRAF-V600E mutation in the samples was related to decreased levels of glycerol compared to tumors bearing only wild-type alleles of this gene. No metabolic differences were observed between recurrent ameloblastomas and primary ameloblastomas. It is concluded that ameloblastoma presents a different metabolomic profile of morphologically normal odontogenic tissue and that the BRAF-V600E mutation may contribute to some metabolic alterations present in the ameloblastoma, which may be related to the pathogenesis of this tumor.

Clinicopathological analysis of oral plasmablastic lymphoma: A systematic review.

BACKGROUND: Plasmablastic lymphoma (PBL) is a high-grade lymphoma that often affects the oral cavity of HIV-positive patients; however, its prognostic determinants remain unknown. PURPOSE: To integrate the available data on oral PBL to determine its clinicopathological features and to identify potential prognostic factors. METHODS: An electronic systematic review was performed using multiple databases with a specific search strategy in February 2018. Inclusion criteria comprised cases diagnosed as PBL affecting the oral cavity and gnathic bones with sufficient data to confirm the diagnoses. RESULTS: A total of 70 publications were included, representing 153 cases. Oral PBL predominantly affected HIV-positive males (76.4%). EBV was observed in 63.4% of the cases. The gingiva was the most involved site and the lesion usually presented as an asymptomatic swelling. Most cases were classified as stage I (21.6%), and chemotherapy alone was applied in 28.8% of the cases. There was a significant association between HIV and EBV infections, and cases affecting HIV-negative patients were more common in older individuals. Cumulative survival of the patients achieved 42.4% and 33.5% after 2 and 5 years, respectively. Although there were no statistically significant clinicopathological parameters in the univariate analysis, the multivariate Cox regression model demonstrated that EBV-positive status, presence of B-symptoms, and chemotherapy alone were independent prognostic determinants of a poor prognosis. CONCLUSION: Oral PBL is an aggressive neoplasm with low survival rates, which is influenced by the presence of EBV, presence of B-symptoms, and with the use of chemotherapy only.