Primary mediastinal B-cell lymphoma: detection of BCL2 gene rearrangements by PCR analysis and FISH

Aggressive Mediastinal Lymphomas

The mediastinum contains essentially all major intrathoracic organs except for the lungs. A variety of both benign and malignant tumors can involve the mediastinum, of which lymphoma is the most common malignancy. Compared to secondary mediastinal involvement by systemic lymphomas, primary mediastinal lymphomas are less common with several specific entities that are mainly confined to mediastinal lymph nodes, and/or thymus. This review will summarize the clinical, histologic, immunophenotypic and molecular genetic features of the most common and most aggressive primary mediastinal lymphomas as well as provide suggested immunohistochemistry panels and differential diagnoses.

Primary mediastinal large B cell lymphoma with coexisting aberrations of C-MYC and BCL-2: a case report and literature review

Primary mediastinal large B-cell lymphoma (PMLBCL) is an aggressive lymphoma characteristic with distinct clinical, morphologic, and immunophenotypic features. The rearrangements of C-MYC, BCL2 and/or BCL6 which are common in diffuse large B-cell lymphoma (DLBCL) are typically absent in PLMBCL. Here we proved a novel case of PMLBCL with concurrent rearrangements of C-MYC and BCL2. Histology showed typical pathomorphological features of PLMBCL. Fluorescent in situ hybridization (FISH) studies showed rearrangements of C-MYC and copy number variation (CNV) of BCL2 gene. It is not well known on the clinical significance of rearrangements of C-MYC and BCL2 genes in PMLBCL. The case gives evidence that cytogenetic testing is necessary for PMLBCLs to get precise clinical evaluation and appropriate treatment.

The basis and rational use of molecular genetic testing in mature B-cell lymphomas

An increasing number of neoplasms are associated with variably specific genetic abnormalities. This is best exemplified by hematological malignancies, in which there is a growing list of entities that are defined by their genetic lesion(s); this is not (yet) the case in mature B-cell lymphomas. However, enhanced insights into the pathogenesis of this large and diverse group of lymphomas have emerged with the ongoing unraveling of a plethora of fascinating genetic abnormalities. The purpose of this review is to synthesize well-recognized data and nascent discoveries in our understanding of the genetic basis of a spectrum of mature B-cell lymphomas, and how this may be applied to contemporary clinical practice. Despite the explosion of new and exciting knowledge in this arena, with the potential for enhanced diagnostic and prognostic strategies, it is essential to remain cognizant of the limitations (and complexity) of genetic investigations, so that assays can be developed and used both judiciously and rationally.