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Blood Research Educational Material
BLOOD RESEARCH
Volume 53ㆍNumber 4ㆍDecember 2018 https://doi.org/10.5045/br.2018.53.4.267Clonal villous lymphocytes and plasma cells in splenic marginal zone lymphoma with plasmacytic differentiation
João Tadeu Damian Souto Filho
1,2, Rodrigo Aires de Morais
2, Ana Laura Oliveira Silveira
1,
Arthur Pires Lacerda
1, Isabela Peçanha Bogado Fassbender
1, João Marcos Marcelino Chaves Ribeiro
1, Luiza Reis de Sales
11Faculdade de Medicina de Campos, Hospital Escola Álvaro Alvim, 2Instituto Federal de Educação, Ciência e Tecnologia Fluminense, Campos dos Goytacazes, Rio de Janeiro, Brazil
Received on March 14, 2018; Revised on April 15, 2018; Accepted on May 10, 2018
Correspondence to João Tadeu Damian Souto Filho, M.D., Faculdade de Medicina de Campos, Hospital Escola Álvaro Alvim, Rua Barão da Lagoa Dourada, 320/1202, Campos dos Goytacazes, Rio de Janeiro 28035-212, Brazil, E-mail: drjoaotadeu@yahoo.com.br
A 42-year-old man presented with low fever, excessive sweating, weight loss, and splenomegaly. His total leukocyte count, hemoglobin level, and platelet count were 2.1×103/L, 10.8 g/dL, and 92×109/L, respectively. Serum protein electrophoresis demonstrated a monoclonal spike and immunofixation confirmed an IgG- monoclonal protein.
Peripheral blood smear revealed 11% small to medium-sized lymphocytes with oval nuclei, mature chromatin, inconspicuous nucleoli, and circumferential cytoplasmatic short villous projections (A, B; Wright-Giemsa stain, ×1,000).
Peripheral blood flow cytometric immunophenotyping revealed a clonal B-cell population expressing cluster of differentiation (CD) 19+++, CD20+++, CD22+++, CD79b++, CD38+, FMC7++, and CD11c++ with light chain. A bone marrow (BM) aspirate smear showed increased plasma cell count (16%) with focal clustering, moderately large and ovoid shape, round and eccentrically placed nuclei, and strong basophilic cytoplasm with a broad perinuclear clear zone without any villous projections (C; Wright-Giemsa stain, ×1,000). No villous lymphocytes were detected. BM flow cytometric immunophenotyping revealed two clonal populations with restricted light chain expression: a clonal B-cell population phenotypically similar to peripheral blood, and a clonal plasma cell population that expressed CD19+++, CD38+++, CD138weak, CD45weak, CD56-, and CD117-. BM biopsy showed nodular interstitial lymphoid involvement and scattered plasma cells. Splenic marginal zone lymphoma with plasmacytic differentiation and villous lymphocytes was diagnosed. Plasmacytic differentiation may occur in almost all low-grade B-cell lymphoproliferative disorders, varying from being rare (mantle cell lymphomas) to being uniformly present (lymphoplasmacytic lymphoma). Distinguishing between myeloma and lymphomas with marked plasmacytic differentiation may be challenging.
