RESUMO
The aim of this study is to present a histopathologic and immunohistochemical analysis of primary gastric lymphomas which were reclassified according to the concept of mucosa associated lymphoid tissue (MALT). The resected specimens from 41 patients with primary gastric lymphoma were investigated retrospectively. Immunohistochemical study was done to analyze the immunophenotype and bcl-2 and p53 proteins expression. Twenty three of the cases had tumors mainly located in the antrum. Histologically, 12 were low grade and 20 were high grade B-cell lymphoma of MALT, 9 other B-cell nonHodgkin's lymphomas. Helicobacter pylori was identified in 72% of the cases. According to Musshoff's modification, most of the MALT lymphoma cases had stage I or II disease. There was significant difference between low and high grade cases, in respect to depth of invasion in gastric wall. Immunohistochemically, the neoplastic cells in all MALT lymphomas expressed B-cell phenotype. Bcl-2 protein was found to be expressed in 59% and p53 protein expression was detected in 72% of cases. Among the B-cell lymphoma of MALT, bcl-2 positivity decreased and p53 positivity increased significantly as the histological grade advanced. So, an inverse correlation was observed between the expression of bcl-2 and p53. In conclusion, most primary gastric lymphomas are low or high grade B-cell MALT lymphomas and appear to arise in MALT acquired as a reaction to Helicobacter pylori infection. Expression of bcl-2 and p53 in gastric lymphomas may be associated with transformation from low-grade to high-grade disease.
Assuntos
Regulação Neoplásica da Expressão Gênica , Genes bcl-2 , Genes p53 , Linfoma de Zona Marginal Tipo Células B/patologia , Linfoma de Células B/patologia , Linfoma não Hodgkin/patologia , Proteínas de Neoplasias/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Neoplasias Gástricas/patologia , Proteína Supressora de Tumor p53/biossíntese , Adolescente , Adulto , Idoso , Antígenos CD20/análise , Antígenos de Neoplasias/análise , Progressão da Doença , Feminino , Gastrite/complicações , Infecções por Helicobacter/complicações , Helicobacter pylori/isolamento & purificação , Humanos , Imunofenotipagem , Metástase Linfática , Linfoma de Células B/complicações , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Linfoma de Zona Marginal Tipo Células B/complicações , Linfoma de Zona Marginal Tipo Células B/genética , Linfoma de Zona Marginal Tipo Células B/metabolismo , Linfoma não Hodgkin/complicações , Linfoma não Hodgkin/genética , Linfoma não Hodgkin/metabolismo , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Neoplasias Gástricas/complicações , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismoRESUMO
Fifty-three patients in the pediatric age group diagnosed as having small non-cleaved follicular center cell (FCC) lymphoma (40 Burkitt's and 13 non-Burkitt's type) have been re-evaluated. Although the histopathologic distinction between the two subgroups is fairly easy to determine there is a considerable degree of clinical overlap in regard to age, sex, anatomic presentation of the disease, the incidence of bone marrow and central nervous system involvement, and the survival. The most important determinant of survival in both subgroups is the stage of the disease.