Follicular<unk>  cells are localized in germinal centers of lymphoid follicles and have an integral role in regulation of the germinal center reaction and present antigens to B cells. Most cases of FDCS develop in the lymph nodes, but about 30% develop in extranodal sites. In 1998 the largest study on the disease was a retrospective review with fifty-one patients. Of these fifty-one patients, no conclusive pattern was found in regard to age, sex, race or presentation. The median patient age was 41 (range 14–76), and while most cases presented with cervical and axillary lymphadenopathy, 17 presented in extranodal sites including the liver, spleen, bowel and pancreas. With such a range of patient histories no definitive cause has been linked to FDCS. There has, however, been some evidence that previous exposure to the Epstein Barr Virus (EBV) or diagnosis of Castleman's disease can increase the risk of developing FDCS—medical literature in 2000 reported approximately 12% of all cases of FDC tumors are associated with EBV, with variance in different organs, but the role of EBV remains unclear in FDC tumor pathogenesis; and EBV does not appear to play a role in the transformation process of Castleman's disease to FDC<unk>  because all cases the report found associated with Castleman's disease were EBV negative. Symptoms of FDCS vary, and are largely dependent on the part of the body in which the tumor develops. The most common symptom is painless swelling in lymph nodes. This symptom alone, however, is nonconclusive, as it is associated with many other diseases, including the common cold. Other symptoms include cough, sore throat, difficulty swallowing, weight loss and tiredness. In cases that present in extranodal sites outside of the head and neck region, organ specific symptoms are observed.
Follicular dendritic cell sarcoma
Langerhans cell sarcoma
Thymic carcinoma
Gray zone lymphoma
Unicentric Castleman disease
Follicular lymphoma
Pleomorphic T-cell lymphoma
Nodal marginal zone B cell lymphoma