A 53-year-old woman, with a history of having been hypertensive for 8 years but displaying no prior record of cardiac illness, came to the hospital with complaints of shortness of breath (class IV) for 1 week. This was aggravated 2 days prior to her visit, associated with orthopnea, a dry cough, and a low-grade intermittent fever. On examination, Pulsus paradoxus and Kussmaul's signs were present.
The ECG showed sinus tachycardia with non-specific ST-T changes. Moreover, the echocardiogram showed massive pericardial effusion with features suggestive of cardiac tamponade and homogenous mass adjacent to the right atrium (Figures 1A, B). Emergency pericardiocentesis was done, and hemorrhagic pericardial fluid was sent for analysis. The patient became asymptomatic; a chest roentgenogram revealed bilateral minimal pleural effusion. Anti-tuberculous treatment was initiated, given the high suspicion of tuberculosis and mildly raised adenosine deaminase levels in the pericardial fluid sample.
CECT thorax (Figures 2A, B) revealed minimally enhancing mass lesion in the right atrial wall with a small intraluminal component projecting into the right atrial chamber, with multiple enlarged retroperitoneal lymph nodes. As it was initially suspected to be lymphoma, a PET CT scan (Figures 2C-F) was performed to rule out metastasis, which showed mildly FDG-avid hypodensity along the lateral wall of the right atrium with mass effect over it.
CT-guided biopsy from the right atrial mass was subjected to histopathological examination. The findings revealed the presence of myxoid liposarcoma (Figure 3A). The histological findings were further confirmed by tumor markers Pan CK and S100, denoting that the sample stained positive for S100 (Figures 3A, B).