Follicular dendritic cell sarcoma: a report of 14 cases and a review of the literature.

Follicular dendritic cell sarcomas (FDCS) are grouped with the histiocytic and dendritic cell neoplasms. The natural history and response to different treatments have not been well established. The cases of 14 patients with FDCS who were seen at M. D. Anderson between 1995 and 2005 were reviewed. Median patient age was 48 years (range, 25-69 years). Histologically, four cases showed low-grade features, three cases showed low-grade features with focal high-grade features, and five cases showed high-grade features. Tumors were positive for CD21, CD23, and CD35 in 83, 90, and 44% of cases, respectively. Twelve (92%) of 13 tumors were strongly positive for epidermal growth factor receptor. Information on initial treatment was available in 11 patients, which included surgery alone in one patient, surgery and radiation in two, surgery and chemotherapy in one, chemotherapy alone in three, chemotherapy and radiation in one, surgery followed by radiation and chemotherapy in three patients. In eight patients the initial chemotherapy regimen was cyclophosphamide, doxorubicin, vincristine, and prednisone. Complete remission was achieved in 7 (63%) of 11 patients. Ten patients were alive at a median follow up of 22 months, 3 (23%) of 13 had no evidence of disease, and 7 (53%) of 13 patients were alive with disease. Follicular sarcoma is an aggressive neoplasm. Although most of the patients initially responded to treatment, the majority of them (81%) relapsed. A better understanding of the biology of FDCS could guide our efforts in the development of new treatment modalities for this rare disease.