1344531 - Metastatic Chondrosarcoma: A Rare Cause of Cardiac Tamponade Diagnosed by Multimodality Imaging

A 43 year-old man with mesenchymal chondrosarcoma of the sacrum, status post treatment, was found to have a cardiac mass on surveillance imaging 6 years after diagnosis.  Given evidence of metastatic disease in other locations, the cardiac mass was presumed due to chondrosarcoma.  After chemotherapy, the patient developed subacute dyspnea on exertion, fatigue, weight gain, and lower extremity edema.

Diagnostic Techniques and Their Most Important Findings:

Transthoracic echocardiogram (TTE) demonstrated a large mass in the right atrioventricular (AV) groove and a circumferential pericardial effusion with late diastolic collapse of the right atrium (RA) (Figure 1).  Cardiac magnetic resonance imaging (CMR) confirmed a large (4.2 cm), well-circumscribed mass in the free wall of the RA and right AV groove (Figure 2).  The mass extended to the tricuspid valve (TV) annulus and encased approximately 5 cm of the mid right coronary artery (RCA).  Cardiac computed tomography angiogram (CTA) showed stenosis of the mid RCA from mass effect (Figure 3).  The patient underwent pericardiocentesis, with removal of 1.1 liters of serosanguinous fluid.  Cytology was negative for malignancy.  Due to improvement in symptoms after pericardiocentesis and risk of right ventricular dysfunction in setting of significant RCA involvement, surgical resection of the mass was not pursued.

The mass increased to 6.2 cm over the next year.  Follow-up TTE demonstrated infiltration of myocardium in the RA and right ventricle, with compression of the TV annulus and right sided chambers.  The patient underwent radiation therapy, but the mass progressed to invade the left atrium.  Unfortunately, the patient suffered multiple embolic strokes and expired.

 

Learning Points from this Case:

Cardiac masses are rare, and metastases are over 100 times more common than primary tumors (1,2).  Clinical presentation may be non-specific, and many secondary tumors are discovered incidentally (1-3).  Though TTE is typically used for initial evaluation, CMR allows for further characterization of extent of cardiac and extra-cardiac disease.  This is especially important for patients undergoing surgical resection (1).  In cases of diagnostic uncertainty, CMR is highly accurate in distinguishing benign masses and thrombi from malignant tumors (4,5).  The presence of late gadolinium enhancement is highly specific for malignant disease (4).

Chondrosarcoma is an exceedingly rare etiology of secondary cardiac tumor, with less than 30 cases reported in the literature (5).  Whereas benign cardiac masses are typically treated with surgical resection, chemotherapy is preferred for metastatic cardiac tumors (1,2).  Despite therapeutic advances, the prognosis of chondrosarcoma with cardiac metastasis is poor, with median survival less than two years after diagnosis (5).