Multimodality imaging of a thymoma within the superior venae cava extending into the right atrium

A 44-year-old female with facial edema and dizziness for six months was admitted to our hospital. Transthoracic echocardiogram showed the dilated superior venae cava (SVC) occluded by a mass. The mass in the SVC was extending into the right atrium (RA) (Fig. 1a–1c, Videos 1-2). Color Doppler flow imaging indicated a narrowed blood flow in the SVC with an increased velocity of 1.6 m/s (Fig. 1d, 1e, Video 3). Contrast-enhanced computed tomography (CT) scan revealed a soft tissue density mass mea suring 9.0×3.3 cm within the SVC extending into the RA (Fig. 2a, 2b). Cardiac magnetic resonance (CMR) imaging demonstrated a heterogeneous mass within the SVC extending into the RA. The mass appeared isointense on the T1-weighted images and slightly hyperintense on the T2-weighted images (Fig. 2c, 2d). Positron emission tomography (PET)/CT scan showed a mass with no significant uptake of 18F-fluorodeoxyglucose (FDG) (Fig. 2e). She underwent the surgical resection of the tumor and a reconstruction of SVC. During the operation, a soft and ashen mass, measuring 10×3×2.5 cm, was found to be located within the SVC extending into the RA (Fig. 2f). Histopathological examination revealed a thymoma (Fig. 2g, 2h). At the six-year follow-up, the patient is well without any evidence of tumor recurrence