METASTATIC DISEASE OF THE SKELETON

Metastatic cancer is among the most frequent causes of skeletal pain a ssociated with a destructive bone lesion or pathologic fracture in adu lts. Patients with a known primary carcinoma should undergo systematic evaluation and monitoring to determine the extent of skeletal disease and risk of pathologic fracture. Patients without a known primary car cinoma who have symptoms consistent with metastatic disease of the ske leton present a diagnostic dilemma. Plain radiographs may not reveal a metastatic lesion until extensive marrow replacement has occurred. Bo ne scans are more sensitive than radiographs and provide a survey of t he entire skeleton. However, increased uptake on a bone scan is not sp ecific and some neoplasms are poorly detected by scintigraphy. Compute d tomography can identify bone destruction or neoplastic bone formatio n that is not easily demonstrated by plain radiographs and can help th e clinician assess the risk of pathologic fracture. Magnetic resonance imaging may be helpful in detecting and defining the extent and preci se location of marrow lesions and soft tissue extension of neoplasms.