Biclonal splenic marginal zone lymphoma with T cell-rich background and aggressive transformation to large cell lymphoma

We report a case of biclonal splenic MZL, T cell-rich variant with an abnormal karyotype that progressed to large B cell lymphoma. A 74-year-old female presented with pancytopenia, weight loss, fever, and splenomegaly. Microscopically, the spleen revealed an extensive, vaguely nodular lymphoid proliferation, composed of small lymphocytes, majority of which were reactive T cells. B cells were mostly small and<  5% of total lymphocytes. Focal follicular dendritic cell networks were present, but germinal centers were absent. Flow cytometric analysis revealed two distinct CD5 and CD10 negative B cell clones, one kappa positive and one lambda positive. Conventional cytogenetic analysis revealed the followin g abnormal karyotype: 47,XX,add(7)(q36),del(7)(q22),add(21)(p11.2),+mar[10]/46,XX[10]. Immunoglobulin heavy chain gene rearrangement showed two monoclonal peaks of different magnitude, consistent with biclonality. Overall, these features favored a low-grade splenic MZL. The staging bone marrow biopsy was normocellular with few interstitial lymphoid aggregates, composed of small lymphocytes, consistent with minimal involvement by low-grade B cell lymphoma. The patient improved without adjuvant chemotherapy; however, 12  months later, she developed anemia and lymphocytosis. Subsequent bone marrow biopsy showed extensive involvement by a large B cell lymphoma and complex karyotype with the previously identified abnormalities, as well as additional numerical and structural ab...
Source: Journal of Hematopathology - Category: Pathology Source Type: research