Mantle Cell Lymphoma With Plasma Cell Differentiation

Abstract

The differentiation of B lymphocytes into plasma cells (PCs) is an antigen-mediated process that largely depends on the interaction between B cells and regulatory factors in their microenvironment. Long-lived PCs are derived from activated B cells in the germinal center (GC), whereas PC differentiation from naive B cells occurs in the extrafollicular areas and the PCs are short-lived. Consequently, lymphomas arising from post-GC B cells often exhibit plasmacytic differentiation, whereas lymphomas arising from naive B cells less commonly show plasmacytic differentiation. Herein, we report 2 cases of mantle cell lymphoma (MCL) with clonal PC differentiation. Both cases presented with the typical cytologic features of MCL and were characterized by a nodular and mantle-zone growth pattern. Clusters of clonal PCs with monotypic kappa light chain expression were identified in the centers of the tumor nodules and within reactive GCs. FICTION (Fluorescence immunophenotyping and Interphase Cytogenetics as a Tool for the Investigation Of Neoplasms) analysis demonstrated the characteristic t(11;14)(q13;q32) in both the MCL cells and clonal PCs, indicating that both cell types were derived from the same B-cell clone. These findings indicate that the clonal PC differentiation may occur within GCs in some cases of MCL.

Bortezomib resistance in mantle cell lymphoma is associated with plasmacytic differentiation

“…In these reports, clonally related B cells and fully differentiated plasma cells showing t (11;14) have been found to coexist. [50][51][52] One case showed 3 discernible populations including a B-cell population in transition to plasma cells characterized by coexpression of CD19, CD38, and CD138. 51 These cases may be extremes, but illustrate the ability of MCL cells to differentiate into plasma cells.…”

Mantle cell lymphoma

“…Clusters of plasma cells can be seen: they are usually reactive (polytypic at immunohistochemistry), only exceptionally representing a feature of tumor differentiation with obvious monoclonality and tendency to accumulate in the center of lymphomatous nodules. 14 The number of mitotic figures varies, although it is usually low to moderate (see below).…”

Plasma cell and terminal B-cell differentiation in mantle cell lymphoma mainly occur in the SOX11-negative subtype

“…29 However, occasional mantle cell lymphomas with focal areas of plasma cell differentiation have been reported. [30][31][32] These studies have emphasized the presence of mature clonally related plasma cells in otherwise classical mantle cell lymphoma but the potential relationship to SOX11 expression is not known. On the other hand, the expression of transcription factors regulating the switch from mature B-cell to plasma cells such BLIMP1, IRF4/MUM1 and XBP1 have not been well investigated in these tumors.…”