Bcl-2 maturation pattern in T-cells distinguishes thymic neoplasm/hyperplasia, T-lymphoblastic lymphoma, and reactive lymph nodes.

Anterior mediastinal biopsies consisting predominantly of small lymphocytes can be a diagnostic challenge, especially in small core biopsies. In these cases, immunophenotyping is often employed using flow cytometry, and/or immunohistochemistry. However, due the overlap in T-cell phenotype between thymic neoplasm/hyperplasia (THY), T-lymphoblastic lymphoma (T-LBL), and reactive lymph nodes (RLN), biopsies consisting predominantly of T-cells may still be difficult to differentiate. Previous studies have shown a specific CD3/bcl-2 staining pattern in thymic T cells of humans and mice using flow cytometry. However, the utility of this finding in distinguishing T-cells of THY, T-LBL, and RLN has not been carefully evaluated. Our findings show that the pattern of CD3/bcl-2 expression in thymic T-cells can be used to help diagnose anterior mediastinal biopsies, even when limited specimen is provided. © 2017 International Clinical Cytometry Society.