Présentation hématologique des lymphomes A cellules B matures (Ganglionnaires et extra-ganglionnaires)

Mature B-cell lymphomas constitute a group of heterogeneous entities concerning biological, clinical and prognostic data. Bone marrow and blood involvement is present with a quite variable level, and is observed essentially in small B-cell lymphomas. A rigorous cytological analysis of cell characteristics, with the help of immuno-phenotyping, allows in the majority of the cases to discriminate small B-cell lymphomas from chronic lymphocytic leukemia, and to propose a precise subtyping, follicular lymphoma, mantle cell lymphoma ou marginal zone lymphoma. With this aim, blood samples must be preferred to bone marrow smears on account of an optimal preservation of cell characteristics, under the condition of adequate spreading and staining. Bone marrow analysis keeps a diagnostic value when blood dissemination is absent or too low for a diagnostic purpose. However one must be aware of rare diagnostic pitfalls occurring even after complete investigations including karyotype; this points to the fact that tissue biopsy is necessary, whenever is possible, especially in case of nodal localizations, providing topographic data and additional immunological markers, not available in flow cytometry.