Objective. To evaluate the conventional X-ray and MR imaging features
of malignant fibrous histiocytoma (MFH) of bone. Design. MRT examinati
ons and conventional radiographs were reviewed in 39 patients with bio
psy-proven MFH. Imaging characteristics were analyzed and the differen
tial diagnoses assessed in a masked fashion by two experienced radiolo
gists. Results. Typical X-ray features included aggressive, destructiv
e tumor growth centrally located in the metaphysis of long bones. Peri
osteal reactions and expansive growth were rarely seen. On MR images e
xtraosseous tumor spread was frequently noted. On T2-weighted images a
nd contrast-enhanced T1-weighted images most of the tumors displayed a
n inhomogeneous, nodular signal pattern with peripheral Gd-DTPA enhanc
ement. Conclusions. Although several MR imaging criteria were typical
for MFH none of them was specific. Xray diagnosis of MFH may also prov
e difficult, with the main differential diagnosis being metastasis in
the older and osteosarcoma in the younger population.