Rapidly progressive respiratory failure with multiple halo signs on computed tomography in a patient with primary cardiac angiosarcoma derived from the right atrium: a case report

BACKGROUND: Primary cardiac neoplasms are extremely rare, with an autopsy incidence of 0.0001–0.003%. Primary cardiac sarcoma is usually derived from the right atrium and it manifests as chest pain, arrhythmia, hemoptysis, dyspnea, and fatigue. The most common target organ for metastasis of primary angiosarcoma is the lungs, but the radiological-pathological correlation has been rarely reported. CASE PRESENTATION: A 38-year-old healthy Japanese man was admitted to our hospital with persistent hemoptysis, exaggerated dyspnea, and two episodes of loss of consciousness in the past 3 months. Non-enhanced thoracic computed tomography (CT) revealed multiple scattered nodules with halo signs. Contrast-enhanced thoracic CT revealed a filling defect in the right atrium, which corresponded to the inhomogeneously enhancing tumor in the right atrium on enhanced electrocardiogram-gated cardiac CT. On day 2, acute respiratory failure occurred, and the patient was placed on mechanical ventilation. The patient was diagnosed with primary cardiac angiosarcoma based on the urgent transcatheter biopsied specimen of the right atrium mass and was treated with intravenous administration of doxorubicin. However, his respiratory status rapidly deteriorated, and he died on day 20. Postmortem biopsy showed that the multiple lung nodules with the halo signs corresponded to the intratumoral hemorrhagic necrosis and peripheral parenchymal hemorrhage in their background, suggesting the fragility of the lung tissue where the tumor had invaded, which caused hemoptysis. Furthermore, two episodes of loss of consciousness occurred probably due to a decreased cardiac output because of a massive tumor occupying the right atrium, recognized as an inhomogeneous centripetal enhancement on enhanced electrocardiogram-gated cardiac CT. CONCLUSIONS: This case clearly demonstrated that primary cardiac angiosarcoma could expand in the right atrial cavity, which led to a decreased cardiac output resulting in repeated syncope, together with the fragility of lung tissue by tumor invasion, thereby generating a halo sign on thoracic CT.