[Clinicopathologic features and differential diagnosis of splenic B-cell marginal zone lymphoma involving bone marrow].

[waldenstrÃ¶m macroglobulinemia]

To study the clinicopathologic features and differential diagnosis of splenic B-cell marginal zone lymphoma (SMZL ) involving bone marrow .The clinical and pathologic features of 22 patients with SMZL were retrospectively studied . Immunophenotypic analysis was carried out by flow cytometry and immunohistochemistry . Immunoglobulin heavy chain rearrangement study was performed using polymerase chain reaction-based method .Villous lymphocytes were found in peripheral blood smears of 11 /18 of the patients . In bone marrow aspirates , lymphocytosis (> 20 %) was demonstrated in 15 cases (15 /18 ) and villous lymphocytes in 6 cases (6 /18 ). Flow cytometry showed CD 19 (+) CD 2 0 (+) FMC 7 (+) CD 22 (+) CD 10 (-) CD 2 (-) CD 3 (-) CD 7 (-) in 18 cases . Bone marrow biopsies of all the 22 patients revealed various degrees and patterns of neoplastic infiltration , as follows : mild (4 cases , 18 .2 %), moderate (11 cases , 50 .0 %) or severe (7 cases , 31 .8 %); intrasinusoidal (16 cases , 72 .7 %), interstitial (14 cases , 63 .6 %), nodular (11 cases , 50 .0 %) or diffuse (1 case , 4 .5 %). Reactive germinal center formation (CD 2 3 (+) bcl-2 (-)) was found in 2 cases (91 .0 %). Immunohistochemical study showed the following results : CD 2 0 (+) PAX 5 (+) CD 3 (-) CD 5 (-) CD 10 (-) cyclin D 1 (-) CD 2 3 (-) CD 4 3 (-) Annexin A 1 (-) CD 11 C (-) CD 2 5 (-) in all the 22 cases , CD 38 (+) in 2 cases (9 .1 %) and CD 138 (+) in 2 cases (9 .1 %).Different and overlapping patterns of bone marrow involvement are observed in SMZL . As the histologic and immunophenotypic features are not specific to SMZL , distinction from other types of mature B-cell lymphomas is necessary .