Molecular diagnosis of B- and T-cell lymphomas: fundamental principles and clinical applications

Abstract

Molecular diagnostic assays have become routine in the evaluation of lymphoid malignancies. Both Southern transfer and polymerase chain reaction (PCR) technologies are used to assess for B- and T-cell clonality, the presence of rearrangements involving protooncogenes such as bcl-1 and bcl-2, and the monitoring of minimal residual disease. We review the fundamentals of B- and T-cell ontogeny as well as the basic principles of the Southern transfer and PCR assays and their applications to the diagnosis of lymphoid malignancies.

Diagnosis of peripheral T-cell lymphoma by fine-needle aspiration biopsy: A cytomorphologic and immunophenotypic approach

“…Alternatively, expression of immature T-cell-associated antigens (e.g., CD1 and CD2) constitutes an aberrant T-cell phenotype. 3,[13][14][15][16][17][18][19][20] In this study, 16 (80%) cases showed aberrant T-cell antigen loss and/or expression. Two cases that showed abnormal T-cell antigen expression by flow cytometry were negative by PCR, confirming the false-negative rate in gene rearrangement studies.…”

“…However, it is expressed in 85% of normal T-cells, and therefore its absence is not an unequivocal evidence of malignacy. 3,22,23 The presence of another immunophenotypic abnormality improves the ability to render the diagnosis of malignancy. In our study, CD2 and CD3 were the least common to be lost.…”

“…This is mainly due to the rarity of the disease, morphologic similarities to reactive lymphadenopathy, and difficulties in identifying abnormal T-cell antigens. 2,3 Fine-needle aspiration biopsy (FNAB) coupled with flow cytometric immunophenotyping are powerful diagnostic tools that are increasingly being utilized in the diagnosis of non-Hodgkin's lymphomas, including, T-cell lymphomas. 4 -9 FNAB is a simple, minimally invasive, and relatively inexpensive procedure.…”

Automated kappa and lambda light chain mRNA expression for the assessment of B‐cell clonality in cutaneous B‐cell infiltrates: its utility and diagnostic application

“…25 The cells usually express CD20, CD43, and bcl-2 but do not express CD5, CD10, or CD23. 14,[26][27][28][29] The most common forms of 2 CBCL are either of FCC origin and express CD10 or represent CD5 þ small round lymphocyte infiltrates of SLL/CLL type. 12 There are cases of cutaneous lymphoma where the combined light microscopic and phenotypic profiles create uncertainty with respect to diagnosis and classification.…”

“…Furthermore, the Although T-cell clonality may be seen in non-neoplastic processes, B-cell clonality in cutaneous lymphoid infiltrates correlates highly to malignant lymphoma. 29 In any of these scenarios, clonality studies would be particularly helpful.…”