Floral leukemic cells transformed from marginal zone lymphoma

Abstract

There are three clinicopathological entities of marginal zone lymphoma (MZL), including extranodal or mucosa-associated lymphoid tissue (MALT) lymphoma and MZL of nodal (NMZL) or splenic (SMZL) type. Of these, leukemic presentation, usually as small or villous lymphocytes, is more common in SMZL, while leukemic change in NMZL is rare, and the morphology has not been characterized. We present a stage 4 MZL involving lymph node, spleen, and bone marrow with two relapses after chemotherapy. The leukemic cells at the second relapse revealed irregular nuclear contours with multilobated nuclei (so-called flower cells or floral cells) mimicking the neoplastic cells in adult T-cell leukemia/lymphoma (ATLL). The absence of leukemic change and splenic hilar lymphadenopathy at initial presentation, expression of IgD by tumor cells, and cytogenetic changes of +7 suggested that this tumor might be a NMZL. Although the cytomorphologic features of floral leukemic cells might suggest ATLL, thorough clinical and laboratory workup helped to reach a correct diagnosis. Our findings broaden the cytological spectra of leukemic cells in MZL and illustrate the importance of immunophenotyping.