Abstract
We report a case of de novo diffuse large B-cell lymphoma (DLBCL) in leukemic phase, positive for both CD5 and CD13. Morphologic evaluation, flow cytometric immunophenotyping, karyotyping and polymerase chain reaction studies were performed. Neoplastic lymphocytes appeared as blast-like cells, positive for CD19, CD20, CD5, CD13, CD79a, HLADR, and with restriction for surface immunoglobulin K light chains. Rearrangement of IgH gene, BCL2/IgH translocation and complex karyotype were found. The patient was treated with RCOMP regimen and achieved complete remission. However, only one month after the first restaging of disease, the patient presented with symptoms attributable to central nervous system involvement and her clinical conditions worsened rapidly. While both CD5 expression and leukemic presentation are uncommon findings in DLBCL, positivity for CD13 is very rare. The outcome of our patient shows the poor prognosis of CD5+ DLBCL with leukemic presentation. The possible role of CD13 coexpression is discussed.