the incidence of primary cardiac tumors is very low , less than 0.3% of autopsies .
primary sarcomas of the heart are very rare and constitute less than 25% of primary cardiac tumors , among which rhabdomyosarcomas are the rarest.1 clinical presentation , such as arrhythmia , precordial pain , and pericardial effusion , is not specific and depends on the location of the tumor and intracavitary obstruction to blood flow .
patients are sometimes asymptomatic until the appearance of metastasis , which leads to diagnosis.2 despite different treatments ( surgery , chemotherapy , or radiotherapy ) , the survival period for patients with cardiac sarcomas is limited from six months to two years
. we present a case of cardiac rhabdomyosarcoma , which was incorrectly presented as a mediastinal tumor by computed tomography ( ct ) .
the final diagnosis was conducted via endoscopic ultrasonography ( eus ) , which identified the lesion as a cardiac tumor .
the diagnosis was further confirmed histologically by eus - fine needle aspiration ( fna ) .
a 76-year - old woman was admitted to our institution because of a reported mediastinal tumor .
chest radiography and ct scan revealed a bulky mediastinal tumor , with a size of 77 mm  44 mm  40 mm ( figure 1 ) .
moreover , ct scan showed small cervical lymph nodes ( less than 10 mm ) but did not find hepatic or lung metastasis .
eus ( fg 36x , pentax , japan ) found a large mass above the cardia and revealed that the tumor developed from the left atrium ( figure 2 ) , which explained the rhythm dysfunction .
we performed a trans - esophageal puncture with a 19-g needle ( echotip , cook corporation , limerick , ireland ) during examination ( figure 3 ) .
histological and immunohistochemical analyses of the sample revealed a cardiac rhabomyosarcoma ( positive vimentin and anti - myoglobin antibodies ) .
the patient underwent chemotherapy ( doxorubicin 50 mg / m every 3 wk ) and achieved a partial response ( 43% decrease in the tumor ) after 8 cycles .
eus image showing the tumor that ( t ) developed from the left atrium ( la ) , below the pulmonary artery ( pa ) .
eus image showing the puncturing of the left atrium 's tumor with a 19 g needle ( cook ) .
she is still alive and without any arrhythmia 17 months after the discovery of the tumor .
cardiac rhabdomyosarcomas are very rare tumors ( overall incidence less than 0.07%),3 representing less than 25% of all primary malignant neoplasms of the heart.4 the tumor produces a large variety of symptoms , such as arrhythmia and pericardial effusions , among others.5 its prognosis is very poor.1 the diagnosis is primarily performed via trans - esophageal echocardiography and less frequently via ct scan,6 but final diagnosis is obtained during surgery or autopsy .
two - dimensional , doppler , and standard transesophageal echocardiography can only describe the tumor 's location and size , movements , ventricular function , and hemodynamic disorders.7 however , difficulties arise in accessing the tumor extension in mediastinal structures to distinguish between a primary cardiac tumor and a mediastinal tumor infiltrating the heart or differentiate the tumor from a thrombus .
ct scan or magnetic resonance imaging ( mri ) can precisely locate the tumor , but not in our case report .
t2- weighted sequence mri and/or the injection of contrast could only allow suggestions toward the histological nature in rare cases , such as lipomatous tumors .
however , this method does not permit distinguishing between malignancy and benignity and the diagnosis.1 the main advantage of eus and eus - fna is their ability to obtain , during the same procedure , a precise location and a histological characterization of the tumor .
although no similar case has been reported , the overall accuracy of eus - fna for mediastinal masses or lymph nodes is 90% to 95% . in our case report
, we obtained histological samples , which permitted immunohistochemical studies , i.e. , the vimentin and the anti - myoglobin antibodies .
eus - fna of heart tumors is possible without any complication and can prevent the morbidity and mortality of a diagnostic thoracotomy.2
an unusual indication of eus resulted in a more precise diagnosis than ct scan that indicates the presence of 
 a cardiac , but not a mediastinal , tumor .
in addition , a histological diagnosis via eus - fna without need for surgery allows the patient to benefit from a fast and optimal medical treatment .
 we report a case of cardiac rhabdomyosarcoma , with initial clinical features of  atrial rhythmic dysfunction  , which was concluded as a mediastinal tumor by computed tomography ( ct ) scan . 
 endoscopic ultrasonography ( eus ) and eus - fna ( fine needle aspiration ) were initially conducted to diagnose the isolated mediastinal mass . in this case , 
 eus re - assessed the previous diagnosis as a cardiac tumor , and the patient eventually achieved a 17-month survival rate after chemotherapy . in this paper , 
 eus findings obtained in our case are described and a review of literatures is briefly discussed . 
 we also describe the advantages and limitations of this technique compared with other image diagnosis alternatives . 
Introduction
Case report
Discussion
Conclusion