Fig. 1

Right atrial lipoma. a MIP of ¹⁸F-FDG PET/CT revealed lung cancer with increased ¹⁸F-FDG uptake in the right upper lobe (black arrow). b–d The transverse and e–g coronal view of selected PET, CT, and fused PET/CT images revealed a well-circumscribed solitary mass, which located in the right atrium (white arrow, SUVmax 0.8). h On the non-contrast CT, the tumor presented as sharply margin, ovoid shape with fat density; the CT attenuation value was − 50 HU (white arrowhead). i–j The transverse view of arterial and venous phases of CECT images revealed no enhancement of the tumor