[A marginal zone-B cell lymphoma revealed by platelet satellitism and lympho-agglutination phenomenon around atypical lymphocytes].

A 48-year-old man, with persistent pyrexia, presented with thrombocytopenia and lymphocytosis. The peripheral blood smears showed atypical lymphocytes and a platelet satellitism phenomenon around atypical lymphocytes associated to lympho-agglutination. Platelet satellitism was exclusively observed with atypical lymphocytes in EDTA-treated blood and at room temperature. This phenomenon was not observed when adding normal plasma and could be reproduced several times. Flow cytometry analysis of the peripheral blood, cytological and histological studies revealed a marginal zone-B cell lymphoma. The mechanism underlying platelet satellitism is not fully understood, but is likely to involve an immunologic binding of EDTA-dependent antiplatelet autoantibodies directed against the platelets glycoprotein IIb/IIIa complex. The association between platelet satellitism and lymphoma could also involve a monoclonal Ig secreted by lymphoma cells.