PMLBCL : Molecular Genetics

Comments:
Molecular Genetics - Primary mediastinal large B-cell lymphoma (PMLBCL) has clonally rearranged immunoglobulin heavy chain and light chain genes and germline TCR genes. Rearrangements of CCND1, BCL2, BCL6, and MYC are rare or absent. BCL6 mutations are present in up to 70% of cases.

Gene expression profiling studies show that PMLBCL is more closely related to classic Hodgkin lymphoma (cHL) than diffuse large B-cell lymphoma, NOS. One-third of genes overexpressed in PMLBCL are also highly expressed in cHL. These genes are involved in NF-κB and JAK-STAT signaling pathways (discussed in subsequent images).

The image shows delicate collagen fibrils criss-crossing the tumor. The cells have moderate to abundant clear cytoplasm.