Background: Although hematogenous spread of osteosarcoma is well known, the imaging findings of cardiovascular involvement by osteosarcoma are seldom reported and can be difficult to recognize. The enhanced resolution of modern CT and MRI scanners may lead to better detection of cardiovascular involvement.
Objective: To describe the key imaging findings and clinical behavior of cardiovascular involvement by osteosarcoma.
Materials and methods: We retrospectively reviewed the imaging findings and clinical characteristics of 20 patients with cardiovascular involvement by osteosarcoma identified by two pediatric radiologists from a review of imaging studies at our institution from 2007 to 2013.
Results: At initial diagnosis, the median age of the patients was 15.1 years (range 4.8-24.6 years), and 7 (35%) patients had detectable metastases. Median time to detection of cardiovascular metastases was 1.8 years (range 0-7.3 years). Sixteen patients died of disease; 4 have survived a median of 7.4 years since initial diagnosis. The sites of cardiovascular involvement were the systemic veins draining the primary and metastatic osteosarcoma, pulmonary arteries, pulmonary veins draining the pulmonary metastases, and heart. A dilated and mineralized terminal pulmonary arteriole is an early sign of metastatic osteosarcoma in the lung. Unfamiliarity with the imaging features resulted in under-recognition and misinterpretation of intravascular tumor thrombus as bland thrombus.
Conclusion: Knowledge of imaging findings in the era of modern imaging modalities has enhanced our ability to detect cardiovascular involvement and lung metastases early and avoid misinterpreting tumor thrombus in draining systemic veins or pulmonary arteries as bland thrombus.
Keywords: Children; Computed tomography; Heart; Inferior vena cava; Magnetic resonance imaging; Osteosarcoma; Positron emission tomography-computed tomography; Superior vena cava; Tumor thrombus; Vascular metastasis.