This is a recently recognized rare tumor that has been reported as reticulum cell sarcoma, sarcoma of follicular dendritic cells, among others. It is a tumor arising in the follicular dendritic cells of lymph nodes. The reticulum cells in lymphoid tissue may differentiate along a few lines - histiocytic, fibroblastic or dendritic/interdigitating. Dendritic and interdigitating cells are antigen processing cells that express CD1, CD21 and variably CD68 and S-100 protein. In the studies reported thus far, patients have been treated with a variety of modalities, including chemotherapy, radiation and/or surgery.
Contributed by Jeff Nine, M.D., Leon Barnes, M.D. and Steven Swerdlow, M.D.