Right Atrial Paraganglioma: An Extremely Rare Primary Cardiac Neoplasm Mimicking Myxoma

Abstract

In this report, we present a case of 35-year-old lady who had presented with atypical chest pain and exertional breathlessness for past six months. Transthoracic and transesophageal echocardiograms showed a well-circumscribed, echo-dense mass in the right atrium, attached to the interatrial septum at the level of atrioventricular junction and in the vicinity of coronary sinus ostium. She underwent successful resection of the cardiac mass. Histopathology revealed paraganglioma, which was reconfirmed by immunohistochemistry study. This represents an extremely rare presentation as primary cardiac tumors are 20-times less common than metastatic tumors and paraganglioma is one of the rarest primary cardiac tumors, accounting for < 1% of all cases.

Keywords: Cardiac mass; Neural crest tumor; Pheochromocytoma; Primary cardiac tumor.

Fig. 1. Echocardiographic images of the right atrial mass. Transthoracic echocardiogram (A) and transesophageal echocardiogram (B).

Fig. 2. Intraoperative findings. The tumor is seen within the right atrium (A) and excised mass (B).

Fig. 3. Histopathology of the excised mass showing polygonal cells with moderately pleomorphic nucleoli and moderate eosinophilic cytoplasm, suggestive of a paraganglioma (hematoxylin and eosin staining).

Fig. 4. Immunohistochemistry of the excised mass. Positive for chromogranin (A) and positive for synaptophysin (B).