“…[ 12 , 25 ] The differential diagnosis include: sarcoma, Hodgkin disease, leiomyosarcoma, gastro-intestinal stromal tumor (GIST), and inflammatory pseudo-tumor. [ 8 , 26 , 27 ] According to IHC analyses, FDC sarcoma shows spindle tumor cells arranging in fascicular or storiform patterns, which are immuno-reactive for one or more FDC markers: CD21 (C3d receptor, positive in 93% of cases) and CD35 (C3b receptor, positive in 89% of cases). Other quite specific markers used are: R4/23 (63%), Ki-67 (5–50%), EMA (41%), Vimentin (61%), HLA-DR (57%), CD45 (21%), and S-100 protein (31%).…”