Malignant fibrous histiocytoma of soft tissue producing granulocyte colony-stimulating factor

We treated a rare case of malignant fibrous histiocytoma (MFH) of soft tiss ue that produced granulocyte colony-stimulating factor (G-CSF). The patient , an 80-year-old woman, was admitted because of a feeling of abdominal full ness and leg edema. An elastic, hard, tender tumor was palpated in the righ t thigh. Histopathological examinations of the tumor revealed atypical and prominent pleomorphic spindle-shaped cells with funicular arrangement, whic h were compatible with the diagnosis of MFI-P. Prominent leukocytosis (up t o 84,300/mul), a high serum G-CSF concentration (82 pg/ml) and positive imm unohistochemical staining of the tumor tissue for G-CSF indicated that G-CS F was produced by the MFH.