MALIGNANT FIBROUS HISTIOCYTOMA OF BONE - CONVENTIONAL X-RAY AND MR-IMAGING FEATURES

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.