Most cases of follicular lymphoma, especially those rich in small-cleaved cells, have a t(14;18) gene translocation. This results in a rearranged and constitutively over-expressed gene called BCL-2. 

Follicular Cell Lymphomas: A Breakdown

Follicular lymphomas are divided into 3 types according to the ratio of small-cleaved and large cells:

1. Small-cleaved cell type has less than 20-25% large cells, or
fewer than 5 large cells per high power field. This lymphoma is rich in small-cleaved cells, which know how to voyage in the blood and are often found there as well as in the marrow and liver. Patients nevertheless have a median survival of 7.5-9 years. As in other indolent lymphomas, however, standard chemotherapy cannot secure a protracted remission or cure.

2. Mixed small-cleaved and large cell type has between 20-25% and 50% large cells or between 5 and 15 large cells per high
power field. Though these lymphomas are also indolent (low grade in the Working Formulation), the increased percentage of large cells is associated with a reduced average survival.

3. Large cell type has more than 50% large cells, or more than 15 large cells per high power field. Large cell lymphomas with a follicular growth pattern are uncommon, and the nodularity can be hard to perceive. These lymphomas are the only intermediate grade follicular lymphomas - they are classified as indolent but their aggressive nature is noted by NCI.

Treatment

Treatment options depend on the stage and grade of the disease. The infrequent adult patients with early-stage disease may be treated with local radiation, with or without chemotherapy. Patients with more advanced but low-grade disease may remain untreated as long as no symptoms or lymphoma-related organ compromise are present (watch and wait). When treatment becomes necessary, the options include:

Further Reading

Non-Hodgkin's Lymphomas, Peter M. Mauch (Editor), James O. Armitage (Editor), et al., 2004.

• Section IV: Pathology, Biology, Clinical Evaluation, and Treatment Section
  • Chapter 24: Follicular Lymphoma
    

Living With Lymphoma, Elizabeth Adler, Oct. 2005

• Chapter 10: Lymphoma Classification and Staging
  Follicular Lymphomas, pp. 298-301
  

Web Sites

• CancerBackup - Follicular Lymphoma (UK) (new name)   
• The Hematopathology site has a great, often times technical, discussion of follicular lymphoma. 

Survivor Sites

• Robert Miller is a survivor of follicular and diffuse lymphoma with articles on his site.

Mailing Lists

• See the mailing list page for NHL (many) and Follicular (1) mailing lists  

Reference Sources

• NCI Non-Hodgkin's Lymphoma Information  
• The Hematopathology discussion of follicular lymphoma  
• A paper in the Cancer Control Journal: Indolent Lymphomas: Classic Subtypes and Newer Entities
• Frontiers in Bioscience is a source of B-cell information.
• ESMO Clinical Recommendations for newly diagnosed follicular lymphoma