Résumé
<p><b>OBJECTIVE</b>To study clinicopathologic and genetic features of anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma (LBCL).</p><p><b>METHODS</b>Light microscopy, EliVision immunohistocheimical method and fluorescence in-situ hybridization were used to evaluate three ALK + LBCL cases recently diagnosed accompanied with a literature review.</p><p><b>RESULTS</b>All three cases were male adult patients (mean age = 36.3 years) with nodal involvement by lymphoma. Histologic evaluation revealed a diffuse effacement of the nodal architecture by the infiltration of tumor cells. Sinusoidal infiltration was seen. The neoplastic cells were large and exhibited the immunoblastic/plasmablastic morphology. By immunohistochemistry, all the cases showed a cytoplasmic granular staining of ALK. They were positive for CD45, CD138, and epithelial membrane antigen (EMA), but were negative for CD3, CD20, CD79a and CD30. Fluorescence in situ hybridization (FISH) demonstrated the presence of ALK gene translocation in all of the cases.</p><p><b>CONCLUSIONS</b>ALK + LBCL represents a distinct variant of diffuse large B-cell lymphoma, usually involving lymph node of middle-aged men. The tumor has a immunoblastic/plasmablastic morphology along with a distinct immunophenotypic profile and ALK gene rearrangement.</p>
Sujets)
Adulte , Humains , Mâle , Antigènes CD38 , Métabolisme , Diagnostic différentiel , Immunohistochimie , Hybridation fluorescente in situ , Antigènes CD45 , Métabolisme , Lymphome B diffus à grandes cellules , Génétique , Métabolisme , Anatomopathologie , Lymphome à grandes cellules anaplasiques , Métabolisme , Anatomopathologie , Mucine-1 , Métabolisme , Myélome multiple , Métabolisme , Anatomopathologie , Récepteurs à activité tyrosine kinase , Génétique , Métabolisme , Translocation génétiqueRésumé
The objective of study was to establish an animal model with thymic lymphoma in mice induced by intraperitoneal injection of DNA alkylating agent N-methyl-N-nitrosourea (MNU). Male and female mice of the C57BL/6 strain were injected by the intraperitoneal route with MNU solution in a dosage of 50 mg/kg body weight. The injection was repeated at week 8. Following injection of MNU, the general status of mice was observed. All mice were sacrificed for autopsy at the 22nd experimental week. Complete gross examination was performed for detection of tumor masses. The results showed that at the 22nd week, the incidence of thymic lymphoma in MNU-treated animals was 67.5% (27/40). No significant sex difference in the incidence of thymic lymphoma was observed. In conclusions, an animal model with thymic lymphoma in mice can be established by twice intraperitoneal administration of MNU. The biological behavior of the induced tumors resembles to those of human thymic lymphoma derived from thymic T-cells.
Sujets)
Animaux , Femelle , Mâle , Souris , Lymphomes , 1-Méthyl-1-nitroso-urée , Souris de lignée C57BL , Tumeurs expérimentales , Tumeurs du thymus , Composés triméthylsilylRésumé
The objective of study was to investigate the origin and to classify the subtype of N-methyl-N-nitrosourea (MNU)-induced thymic lymphomas in mice. Histopathologic, immunohistochemical and ultrastructural studies were performed to analyze the pathological features of the neoplasms. The results showed that the thymus in all cases became totally replaced by sheets of cells of the lymphoid series. All the tumors coexpressed CD3 and TdT. Transmission electron microscopic study showed the plasma membranes of malignant lymphoma cells were smooth. The nuclear profiles were usually regular, with varying percentage of convoluted nuclei. Few cell organoids were observed in cytoplasm. In conclusion, all the MNU-induced tumor classified by histopathologic, immunohistochemical and ultrastructural studies as precursor lymphoblastic lymphoma that were unquestionably related to the thymus origin and T-cell lineage.