A 42-year-old man with a history of metastatic primary renal synovial sarcoma (PRSS) presented with 1-week history of dyspnea, ascites, and lower-extremity edema. He had undergone a radical nephrectomy a year before current presentation without any recurrence on surveillance imaging. Physical examination was notable for a grade II diastolic murmur heard best at the left lower sternal border, jugular venous distention, ascites, and lower-extremity edema. Basic laboratory data and 12-lead electrocardiogram were largely unremarkable. Computed tomography demonstrated a nonenhancing mass in the right atrium (RA) abutting into the right ventricle (RV) measuring 3.8 × 7.5 × 3.4 cm (Fig. 1A). In addition, there was a 1.7 × 4.2 × 2.1-cm soft tissue mass extending over the anterior aspect of the inferior vena cava within the prior nephrectomy bed, which was concerning for recurrence (Fig. 1B). An echocardiogram performed 8 months earlier had shown no evidence of an intracardiac mass. Subsequently, transthoracic echocardiography revealed a new large echogenic mass nearly filling the entire RA, prolapsing through the tricuspid annulus into the RV. It measured 6.9 × 3.2 cm (Fig. 2A). He was a poor candidate surgery and received salvage chemotherapy with doxorubicin and dacarbazine. On subsequent imaging, the mass had decreased in size to 4.8 × 2.8 cm (Fig. 2B, Fig. 3). His volume status also improved over the next few months.
Fig. 1.
A) Large right atrial mass. B) A 1.4-cm mass in the right nephrectomy bed with extension of 1.7 × 4.2 × 2.1 cm into the inferior vena cava. Both images are computed tomography scans with contrast.
Fig. 2.
A) A 6.9- × 3.2-cm right atrial mass prolapsing through the tricuspid annulus into the right ventricle. B) This mass shrank to 4.8 × 2.8 cm after chemotherapy. Both images are transthoracic echocardiograms.
Fig. 3.
The reduced mass size in the right atrium after chemotherapy on computed tomography scan with contrast.
Comment
A highly aggressive rare tumor, PRSS represents approximately 1% of all soft tissue tumors.1,2 There has only been 1 reported case of PRSS associated with an intracardiac mass. Although that case had a similar presentation and imaging findings, it described the initial presentation of PRSS that was treated with primary resection and chemotherapy.1 Herein, we report the recurrence of a rare tumor after resection presenting with an intracardiac mass causing obstruction of the tricuspid annulus without significant hemodynamic collapse. Remarkably, the patient had noticeable improvement with only chemotherapy.
Funding Statement
Funding/Support: None
Footnotes
Conflict of Interest Disclosure: None
References
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