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intracardiac masses are commonly encountered clinical entity and include thrombi , vegetations , tumors , inflammatory granuloma , etc . among cardiac tumors ,
although the definite diagnosis of a cardiac tumor can be established only after surgical resection , certain epidemiological and morphological features can help in differential diagnosis of primary cardiac tumors .
myxomas are easiest to diagnose pre - operatively due to their much higher prevalence and characteristic echocardiographic appearance .
however , rarely , some other cardiac tumors can present in a similar manner resulting in misdiagnosis .
we hereby describe a case of a young lady who presented with a right atrial paraganglioma , an extremely rare primary cardiac tumor,1 ) masquerading as a myxoma .
a 35-year - old lady presented to the hospital with atypical chest pain and exertional breathlessness for past six months .
physical examination revealed a pulse rate of 90 bpm , and respiratory rate of 24 breaths / min ; other physical findings were normal .
electrocardiography revealed normal sinus rhythm with t - wave inversion in leads iii and avf .
transthoracic echocardiogram revealed a 1.9  2.4 cm well - circumscribed , sessile , echo - dense mass in the right atrium , attached to the interatrial septum ( fig . 1a , supplementary movie 1 ) .
it showed a larger mass ( 2.4  3.7 cm ) than seen with transthoracic echocardiography ( fig .
the mass was attached near the coronary sinus ostium without causing obstruction to coronary sinus flow .
multiple views of the mass showed hyperechoic tissue density , except for a small area of central echolucency ( supplementary movie 2 ) .
her inferior vena cava was clear . computed tomography of abdomen was also normal . although the homogeneous echodensity of the mass was suggestive of a solid tumor , a presumptive diagnosis of right atrial myxoma was made due to its characteristic location of interatrial septum , high prevalence of atrial myxomas and the patient 's clinical profile .
after detailed preoperative analysis and planning , open - heart surgery for tumor resection was performed on the 3rd day of hospitalization .
intraoperatively , a 2.5  3.5 cm sized , firm , encapsulated , smooth tumor was seen arising from the area between the annulus of the septal leaflet of tricuspid valve and the posterior margin of coronary sinus ostium ( fig .
histopathology of the excised mass using conventional hematoxylin and eosin staining revealed homogeneous polygonal cells with moderately pleomorphic nucleoli and moderate eosinophilic cytoplasm .
the patient was discharged in stable condition with no recurrence of the tumor 4 months later .
myxomas are the most common primary cardiac tumors whereas paragangliomas are amongst the rarest , accounting for < 1% of all cases.1)2 ) paraganglioma is a tumor of neural crest origin and is similar to a pheochromocytoma . for this reason
, paragangliomas are also known as  extra - adrenal pheochromocytoma. mediastinal paragangliomas can be either intracardiac or extracardiac and arise from autonomic neural tissue in these organs .
intracardiac paragangliomas have been found mostly in the left atrium and less commonly in the interatrial septum , left ventricle , anterior surface of the heart , right ventricular outflow tract , or very rarely , right atrium.3 ) to our knowledge , only few cases of right atrial paraganglioma have been described in the world medical literature so far.1)4)5)6)7)8)9 ) clinically , cardiac paragangliomas can present either with symptoms of adrenergic excess or with mass effect.4)7)9 ) mass effect depends on the location and the size of the tumor in relation to cardiac structures .
thus , the patients can present with acute coronary syndrome ( compression of coronary ostium ) , heart failure ( valvular obstruction ) , syncope ( valvular obstruction , compression of great vessels ) , etc.4)5 ) rarely , these tumors may also remain completely asymptomatic .
diagnosis of paragangliomas is most often established after surgical resection only as there are no specific echocardiographic features .
however , in catecholamine secreting tumors , preoperative diagnosis is important because surgical resection of such tumors without prior pharmacological conditioning can lead to disastrous consequences during the immediate postoperative period .
surgery can be quite challenging in these cases due to vascularity of these tumors and their proximity with vital structures .
for obvious reasons , mediastinal and cardiac paragangliomas are among the most technically demanding to resect.10 ) after surgical resection , long - term follow - up is essential , as paragangliomas can recur many years after initial surgery.10 ) our patient did not have any significant mass effect due to the tumor .
further , she probably had a non - secreting tumor because she was not complaining of any symptoms suggestive of catecholamine excess such as hot flush , sweating , headache or intermittent palpitation .
unfortunately , as we did not suspect paraganglioma in this case , we did not check for urine and serum metanephrine levels .
however , in hindsight , we realized that measurement of urine and serum catecholamines should be performed in all primary cardiac tumors , particularly when tumor presents with atypical features and the diagnosis is not readily apparent .
transthoracic echocardiogram showing a large , echo - dense , sessile mass in the right atrium , attached to the interatrial septum at the level of atrioventricular junction .
transesophageal echocardiogram showing a large , echo - dense , sessile mass seen attached to the interatrial septum near coronary sinus ostium .
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 .