THE CURRENT ROLE OF RADIOGRAPHY IN THE ASSESSMENT OF SKELETAL TUMORS AND TUMOR-LIKE LESIONS

Radiography offers more information than any other imaging modality in the study of bone lesions and remains the cornerstone for the differe ntial diagnosis of skeletal tumors and tumor-like lesions thanks to it s higher specificity in detecting tumor morphologic hallmarks, the rad iographic features that help the radiologist make the diagnosis of a b one tumor or tumor-like lesion, or at least narrow the diagnostic poss ibilities, include patterns of bone destruction (geographic, moth-eate n and permeated), lesion margins (from sclerotic rim to ill-defined ma rgin), internal characteristics of the lesion (non-matrix producing tu mors, non-mineralized matrix producing tumors, mineralized matrix prod ucing tumors): type of host bone response (medullary or periosteal), l ocation (femur, tibia, humerus, etc.), site (metaphysis, diaphysis or epiphysis), and position (central, eccentric or periosteal) of the les ion in the skeletal system and in the individual bone, soft tissue inv olvement, and single or multiple lesion nature. Patterns of bone destr uction, margins, and reactive changes in the host bone clearly depict the growth rate of a bone lesion, that is its biologic activity; the m atrix of the lesion, as well as lesion location, site and position may allow a specific diagnosis. This general information coupled with cli nical information helps define whether the lesion is neoplastic or non -neoplastic, benign or malignant, primary or metastatic, and will help further direct the subsequent work-up. CT may be indicated for the op timal assessment of tumor matrix especially in complex anatomical site s, such as the spine, pelvis and hindfoot. The main role of MRI lies i n local tumor staging, especially for planning limb-salving resections . Biopsy is the definitive diagnostic procedure and should be carried out only after the appropriate diagnostic and staging tests. Whenever a bone lesion is suspected, clinical-radiologic-pathologic correlation is essential to make a more accurate diagnosis and to improve patient care. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.