Follicular dendritic cell sarcoma: a rare tumor presenting as an abdominal mass.

Follicular dendritic cell (FDC) sarcoma is a rare and probably even underreported entity. Only approximately some 50 cases have been described in the literature, the majority of which had a lymph node origin. The authors report a case of FDC sarcoma arising within the soft tissues of the abdominal cavity. As FDC markers are often not routinely included in antibody panels, awareness of this sarcoma is important, as it can be confused with other tumors, especially when occurring extranodally.