Onset of Asymptomatic Skeletal Metastatic Disease seen on Dxa

ABSTRACT Objective: Skeletal metastases are common in cancers such as those of the breast, prostate, and lung and most often diagnosed when they come to clinical attention due to pain. We describe two cases of asymptomatic metastatic skeletal disease diagnosed on routine dual-energy X-ray absorptiometry (DXA) evaluation, prompting intervention for the underlying cancer. Methods: Two cases are described, one of breast and one of prostate cancer, with routine DXA imaging studies performed in the setting of cancer therapies that are known to lead to bone loss and fractures, as well as literature review. Results: In the two cases described, significant changes in bone mineral density on DXA demonstrated early asymptomatic metastatic disease, and treatment was initiated for the underlying cancer. In one case, the patient has done well; however, in the second, the patient ultimately succumbed to his disease. Conclusion: The occurrence of skeletal metastases seen on DXA scan had not been previously described with the exception of a recent single case report. These two cases highlight the importance of carefully reviewing all the bone mineral density (BMD) images for unusual gains or losses in cancer patients, as they may herald the onset of asymptomatic metastatic disease. Abbreviations: ADT = androgen deprivation therapy; BMD = bone mineral density; CT = computed tomography; DXA = dual-energy X-ray absorptiometry; MRI = magnetic resonance imaging; PET = positron emission tomography; SREs = skeletal-related events