Diffuse Large B-Cell Lymphoma Activated B-Cell Type

**Semantic type:** Neoplastic Process

**Definition:** A biologic subset of diffuse large B-cell lymphomas with a unique molecular signature or expression profile. It represents approximately 30% of diffuse large B-cell lymphomas, and is characterized by the expression of CD44, PKCbeta1, Cyclin D2, BCL-2, and IRF4/MUM1 genes. Morphologically, these lymphomas are either centroblastic or immunoblastic (ratio 2:1). Patients with this type of diffuse large B-cell lymphoma are reported to have a less favorable outcome compared to those with a germinal center B-cell expression profile, with a 5-year survival rate of 35% and a median survival of 2 years.

**Synonyms:** - ABC DLBCL - ABC-DLBCL - Activated B-Cell-Like Diffuse Large B-Cell Lymphoma - DLBCL Activated B-Cell Type - Diffuse Large B-Cell Lymphoma Non-GC/ABC - Diffuse Large B-Cell Lymphoma Non-Germinal Center/Activated B-Cell Type - Diffuse Large B-Cell Lymphoma with an Activated B-Cell Expression Profile - Non-GC/ABC DLBCL