Small B-Cell Neoplasms With Typical Mantle Cell Lymphoma Immunophenotypes Often Include Chronic Lymphocytic Leukemias

Abstract

Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL) are CD5+ small B-cell neoplasms (SBCNs) with overlapping features. Flow cytometric immunophenotyping is often used to help differentiate CLL from MCL, and a characteristic CLL phenotype is considered essentially diagnostic. However, previous studies have not specifically examined how well a typical MCL immunophenotype distinguishes MCL from CLL. We identified 28 cases of SBCN with typical flow cytometry-determined MCL immunophenotypes consisting mostly of peripheral blood and bone marrow specimens. Fluorescence in situ hybridization analysis indicated that 57% (16/28) had t(11;14) translocations consistent with MCL, while 32% (9/28) lacked t(11;14) translocations but harbored other cytogenetic abnormalities commonly found in CLL. There were no significant morphologic or immunophenotypic differences between the t(11;14)-positive and t(11;14)-negative cases. Our findings suggest that many blood-based SBCNs with typical MCL immunophenotypes likely represent cases of phenotypically atypical CLL, which would have important clinical implications.

Nuclear overexpression of lymphoid-enhancer-binding factor 1 identifies chronic lymphocytic leukemia/small lymphocytic lymphoma in small B-cell lymphomas

“…However, significant overlap in immunophenotype between chronic lymphocytic leukemia/small lymphocytic lymphoma and mantle cell lymphoma, the two major types of CD5 þ B-cell lymphomas, is well recognized. 19,20 CD5 expression in other B-cell lymphomas, such as marginal zone lymphoma and follicular lymphoma, has also been reported. [21][22][23][24][25][26] In addition, rare cases of chronic lymphocytic leukemia/small lymphocytic lymphoma may be CD5À.…”

Atypical case of B-cell Chronic Lymphocytic Leukemia presenting with extreme hyperleukocytosis / Hiperleucocitoză extremă într-un caz atipic de leucemie limfatică cronică cu celulă B

“…The typical CLL also expresses CD23 without FMC7 and shows dim expression of CD20 and dim surface immunoglobulin (sIg) expression. MCL typically expresses bright CD20 and bright to moderate sIg, lacks CD23, and is FMC7+ (16,17,18). Atypical-CLL phenotype is the category of clonal B cells that express CD5, but other markers are differentially expressed as compared with CLL: CD5+CD19+, but CD23 weak of negative or CD20, sIg or CD79b bright (19).…”

Improved flow cytometric detection of ZAP‐70 in chronic lymphocytic leukemia using experimentally optimized isotypic control antibodies

“…Cases were excluded if the immunophenotype deviated from that characteristic of CLL (CD19þ, CD5þ, CD23þ, dim CD20, dim monotypic light chain (17)) or if the viability as assessed by PI exclusion was less than 95% (18). Included cases also needed to have available left over cells following clinical testing, which were cryopreserved as viable cell suspensions in liquid nitrogen for VH mutation analysis.…”