BRAF gene mutations in ameloblastic fibromas / 北京大学学报(医学版)

OBJECTIVE@#To investigate the BRAF gene mutations in ameloblastic fibroma (AF), and to further analyze the relationship between the BRAF mutation and clinical characteristics so as to provide new reference to the study of AF's molecular pathology.@*METHODS@#Sixteen cases diagnosed as AF at the Department of Oral Pathology, Peking University School of Stomatology between January 1990 and December 2017 were collected. Genomic DNA was extracted from formalin-fixed, paraffin embedded tissues using the QIAamp DNA Mini Kit (Qiagen, Germany) according to the manufacturer's instructions. Polymerase chain reaction (PCR) and direct sequencings were used to detect the BRAF gene mutations. The clinicopathological data, such as the age, location of the lesion, symptoms and treatments were retrospectively analyzed.@*RESULTS@#The sixteen cases of AF involved nine women and seven men aged 2-67 years. Three lesions occurred in the maxilla and thirteen in the mandible. The most common presenting symptom of AF was a painless slowly enlarging mass with swelling. Ten patients received conservative treatment and the other six patients received radical surgery. Three cases relapsed during the study period. BRAF gene mutation was found in sixteen of all the sixteen samples analyzed (100%). The BRAF mutation was a point mutation with a thymine-adenine transversion at nucleotide 1 799 of 15 exons, resulting in a change at residue 600 that substituted glutamine for valine. This mutation was the strongest activator of the downstream RAS/RAF/MEK/ERK-MAPK signaling pathway. This helped to bring about a gain-of-function mutation due to a V600E substitution. Many studies identified that BRAF regulated survival, apoptosis, and proliferation of cells by inducing MAPK pathways activation. For the existing cases, none of the age, sex, location, recurrence and treatments had a statistically significant correlation with BRAF mutation.@*CONCLUSION@#Our findings demonstrated high prevalence of BRAF V600E mutation in AF. The pathogenic role remains to be clarified．.

Juvenile hyaline fibromatosis--a rare case report.

Fibromatosis is a group of disorders characterized by infiltrating fibroblastic proliferation. Among them Juvenile hyaline fibromatosis (J.H.F) is a rare, progressive, crippling autosomal recessive disorder diagnosed based on the characteristic clinicopathological findings of generalized cutaneous nodular lesions, gingival hypertrophy, flexion contractures of large joints with osteolytic lesions, and proliferating fibroblasts set within a hyalinized stroma. This disorder commonly manifests in childhood with family history of consanguinity and in siblings. A case of seven year old boy born to consanguinous parents is reported who presented with multiple subcutaneous nodules and gingival hypertrophy. Histopathological examination revealed proliferating fibroblasts embedded in an abundant homogeneous eosinophilic hyalinized matrix. The matrix showed PAS stain positivity, supporting the pathogenesis of this disorder as an inborn error of glycosaminoglycans metabolism. The differential diagnosis is discussed and the literature reviewed.

Uma análise descritiva de tumores do tipo desmoid sarcoma / A descriptive analysis of desmoid tumors

Sarcoma do tipo desmoid é um tumor extremamente raro. As particularidades de suas características clínicas deram origem a um grande número de estudos de caso. Inquéritos sistemáticos sobre a ocorrência deste tumor, entretanto, säo raramente encontrados na literatura médica. Realizou-se, assim, um estudo descritivo de 26 casos confirmados histologicamente de tumores do tipo desmoid, existente e catalogados pelo Hospital e instituto do Câncer M.D. Aderson da Universidade do Texas. Trauma e desequilíbrio endócrino säo discutidos como fatores contributórios do processo de crescimento do tumor desmoid ao tempo em que indicaçöes de que componentes hereditários podem estar envolvidos neste processo säo fornecidas

Fibromatose hialina juvenil múltipla familial: apresentaçäo de duas observaçöes / Multiple familial juvenile hyaline fibromatosis: report of 2 observations

Säo apresentados 2 casos de fibromatose hialina juvenil múltipla familiar em duas irmäs, cujas doenças se iniciaram aos três meses e sete anos de idade, respectivamente, que eram portadoras de tumoraçäo vegetantes com diferentes diâmetros e em números variáveis entre 180 e 250. Em ambas as pacientes, foram demonstradas imagens osteolíticas ao nível dos ossos do crânio, rarefaçäo dos ossos de grandes articulaçöes, limitaçäo de movimentos, principalmente das articulaçöes escapuloumerais e joelhos, contraturas, rigidez da coluna, atrofia muscular e desenvolvimento somático deficiente. Do ponto de vista histopatológico, säo analisados três aspectos diferentes, segundo o estágio da enfermedade