Leukaemoid reaction and eosinophilia in "inflammatory fibrous histiocytoma".

A case of retroperitoneal inflammatory fibrous histiocytoma associated to a marked granulocytic blood reaction and high eosinophilic count is reported. The paraneoplastic nature of the haematological findings and their probable prognostic role are discussed. Ultrastructurally the tumor does not differ significantly from "non inflammatory" fibroxanthosarcomas.