Flow Cytometric and Immunohistochemical Analysis of Small Lymphocytic Lymphoma, Mantle Cell Lymphoma, and Plasmacytoid Small Lymphocytic Lymphoma

Abstract

Small lymphocytic lymphoma (SLL), mantle cell lymphoma (MCL), and SLL plasmacytoid (SLLP) are malignant neoplasms of small B cells that may have overlapping cytologic features. Entities such as SLL with irregular nuclear contours may pose additional diagnostic difficulties. We investigated the utility of flowHistologically, small lymphocytic lymphoma (SLL), mantle cell lymphoma (MCL), and SLL plasmacytoid (SLLP) are lymphomas composed of small lymphocytes. Distinguishing these lymphomas from each other on histologic grounds can be difficult. Particularly when SLL is composed of lymphocytes with irregular nuclear contours, it may be difficult to distinguish SLL from MCL. Yet this distinction is important clinically inasmuch as MCL has a shorter median survival than SLL or SLLP, and it is treated more aggressively than SLL or SLLP.1 Furthermore, it is important to distinguish SLL from SLLP because SLLP is often associated with macroglobulinemia and its hyperviscosity complications. 2Immunophenotypic characterization of these disorders by flow cytometry and immunohistochemistry has been shown to be a useful adjunct to their histologic classification. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] CD23 is a B-cell activation antigen that functions in IgEmediated presentation to T cells 17 and prevents apoptosis of B cells in germinal centers. 18 Recently, assessment of CD23 expression by flow cytometry has been found to be useful in distinguishing SLL from MCL 56 and discriminating SLL from SLLP. 6 By both flow cytometry and immunohistochemistry, CD23 has tended to be present in SLL, absent in MCL) 4,7,10,1U3,19 a n d a b s e n t i n SLLP. 478 ' 13 However, there have been reports of CD23 expression in a majority of SLLP" or MCL cases. 20 The use of anti-CD23 by immunohistochemistry has been successful with frozen section material. Recently, two published studies reported success with anti-CD23 in paraffin-embedded material. 7,21Our objectives in this study were 3-fold: investigate the utility of immunohistochemical detection of CD23 expression in paraffin-embedded material to aid in the distinction of SLL from MCL and SLL from SLLP; investigate whether a battery of other immunophenotypic markers can help in making these distinctions by immunohistochemical and flow 5 8 2

Comprehensive Analysis of Copy Number and Allele Status Identifies Multiple Chromosome Defects Underlying Follicular Lymphoma Pathogenesis

“…using histopathologic, cytologic, and immunophenotypic features (24,25). Thirty-two of the specimens were classified as FL, grade 1, and the remainder were grade 2.…”

Flow cytometric immunophenotyping for hematologic neoplasms

“…26 B-cell lymphoid neoplasms with a CD5 ϩ , CD10 Ϫ phenotype that differs from the typical phenotype of CLL/SLL are more difficult to classify using flow cytometric studies. [27][28][29][30] Although variant phenotypes have been described in CLL/SLL (eg, brighter intensity CD20, brighter intensity surface immunoglobulin, weaker or absent CD23, and expression of FMC-7), additional work-up is generally required to exclude other CD5 ϩ B-cell lymphoid neoplasms. 30 MCL usually demonstrates a CD5 ϩ phenotype that differs from typical CLL/SLL: CD20 moderate to bright intensity, surface For personal use only.…”

Utility of flow cytometry in subtyping composite and sequential lymphoma

“…Morphologic recognition of a second lymphoma component in both cases was facilitated by flow cytometry immunophenotyping. As an alternative to flow cytometry, paraffin-section immunostains using new reagents that identify CD4, CD5, CD8, CD10, and CD23 could have been used to help characterize the lymphoma components of these cases (22,(24)(25)(26). Regardless, results for these cases demonstrate that flow cytometry can provide useful information in evaluating tissue procured from lymphoma patients, even after initial subclassification has been determined.…”