Abstract
A previously healthy 68-year-old woman presented to the outpatient
clinic with a 2-month history of palpitation. Physical examination and
laboratory findings were unremarkable. Her electrocardiogram showed
sinus tachycardia with a heart rate of 115 beats/m. Transthoracic
echocardiography (TTE) showed a normal ejection fraction with a huge
mass in the left atrium (Figure 1a). Transesophageal echocardiography
(TEE) and cardiac magnetic resonance imaging (MRI) were performed for
further evaluation. TEE revealed a hyperechogenic, well-demarcated mass
in the left atrium, that was attached to the interatrial septum and
adjacent to the left pulmonary veins (Figure 1b, 1c,1d). Cardiac MRI
revealed a heterogeneous left atrial mass located on the fossa ovalis,
58x52x54 mm in size and markedly hyperintense on a STIR sequence (Figure
1e). These findings were suggestive of a benign cardiac tumour such as
myxoma or hemangioma. A decision for surgery was made and coronary
angiography was performed which showed that the branch of the circumflex
artery supplied and surrounded the mass in the form of a net (Figure
1e). The patient underwent complete excision of the mass (Figure 2a,
2b). Histopathological examination revealed a nested architecture of
epitelioid cells, the nests are round or oval in shape and invested by
an fibrovascular stroma. Tumor cells had centrally and eccentrically
located round nuclei and cytoplasm ranging from finely granular to
eosiniphilic. At immunohistochemical staining, the nests were positive
for chromogranin A, negative for cytokeratin (Figure 2c, 2d, 2e, 2f). A
diagnosis of paraganglioma was made. After an uneventful postoperative
course, she was discharged home on postoperative day 6. Cardiac
paraganglioma is a very rare neuroendocrine tumour and accounts for less
than 1% of primary cardiac tumours (1,2). Approximately 10% of
paragangliomas may be malignant, complete surgical resection remains the
first-line treatment (3).