From the Guidelines
Follicular center phenotype refers to a specific classification of B-cell lymphomas that originate from or resemble the germinal center B-cells of lymph nodes, characterized by the expression of markers such as CD10, BCL-6, and often BCL-2, as noted in studies 1 and 1.
Key Characteristics
- The follicular center phenotype is not equivalent to follicular lymphoma, as it can also occur in Burkitt lymphoma and some diffuse large B-cell lymphomas (DLBCL) 1.
- Typical immunophenotype includes CD10+, BCL2+, CD23+/-, CD43-, CD5-, CD20+, cyclin D1-, BCL6+ 1.
- Rare cases of follicular lymphoma may be CD10- or BCL2- 1.
Importance of Diagnosis
Understanding the follicular center phenotype is crucial for accurate diagnosis, as it helps distinguish these lymphomas from other B-cell malignancies and guides treatment decisions 1.
Biological Behavior
The phenotype reflects the cell of origin and provides insights into the biological behavior of these lymphomas, which typically follow an indolent clinical course in the case of follicular lymphoma 1.
Treatment Implications
Accurate diagnosis of the follicular center phenotype is essential for guiding treatment decisions, as different lymphomas with this phenotype may require distinct treatment approaches 1.
From the Research
Follicular Center Phenotype
- The follicular center phenotype is associated with follicular lymphoma (FL), a type of non-Hodgkin's lymphoma that originates from the follicular center B cells 2.
- Follicular center cell (FCC) lymphomas are characterized by the presence of surface immunoglobulin (Ig) and the absence of E rosette-forming cells, indicating their B-cell origin 2.
- The follicular center phenotype is typically marked by the expression of specific surface antigens, such as CD19, CD20, and CD10, as well as the presence of monoclonal immunoglobulin 3.
- The diagnosis of follicular lymphoma is based on histology from a biopsy of a lymph node or other affected tissue, and immunohistochemical staining is used to confirm the follicular center phenotype 3.
Immunologic Characteristics
- Follicular center cell lymphomas are characterized by the presence of surface IgM, IgD, IgG, or IgA, and light-chain analysis shows a predominant light-chain type, indicating their monoclonal nature 2.
- The neoplastic cells from follicular center cell lymphomas synthesize the surface Ig they bear, and the Ig-bearing cells have a polyclonal distribution in reactive tissues 2.
- The follicular center phenotype is also associated with the expression of specific genes, such as the t(14;18) translocation involving the IgH/bcl-2 genes, which is present in the overwhelming majority of cases 3.
Clinical Significance
- The follicular center phenotype is an important prognostic factor in follicular lymphoma, and the diagnosis and treatment of this disease are based on the characterization of the follicular center cells 3, 4, 5, 6.
- The treatment of follicular lymphoma typically involves the use of rituximab, a monoclonal antibody that targets the CD20 antigen on the surface of B cells, including those with the follicular center phenotype 3, 4, 5, 6.