This study describes a 79 year-old female suffering from fever and lymphadenopathy. A lymph node biopsy showed diffuse infiltration of medium-sized cells with plasmacytoid features. The immunologic phenotype determined by cytometric analysis and immunochemistry showed suppressor T antigen (CD2, CD3, CD7, CD8) expression. Absence of CD5 expression characterized this abnormal T cell proliferation. Gamma T cell receptor rearrangement without immunoglobulin heavy-chain gene rearrangement confirmed the T lineage of these plasmacytoid cells and their clonality. Immunological studies are necessary for identification of this T lymphoma with B microscopic findings.