Cardiac tumors may be asymptomatic and found incidentally. Symptoms are usually related to the cardiac location and the tumor size. Cardiac tumors may be presented with constitutional symptoms as fever, weight loss, and fatigue or mass effect that interfere with blood flow, heart valves, and myocardial function resulting in arrhythmias, dyspnea, chest discomfort, or syncope. Also, it may be presented by embolic manifestations. Usually, intracavitary tumors are more symptomatic than intramural tumors [1, 3, 6, 8].
Factors that are helpful in establishing a diagnosis of intracardiac mass are the location of the mass, age at presentation, and imaging characteristics .
RVOT obstruction produced by right ventricular tumors will lead to elevated right-sided pressure and low cardiac output, and patients will present with dyspnea, peripheral edema, hepatomegaly, and ascites. Sometimes, they present with symptoms and signs of pulmonary embolism as the first presentation [3, 9,10,11,12,13].
Our patient admitted to the hospital because of syncope, but she had a history of dyspnea and palpitation on exertion for 2 years before admission. So, early echocardiography is essential for patients with unexplained cardiac symptoms for early diagnosis and management. The existence of a large tumor in the RV cavity and significant elevation of right ventricular pressure due to partial obstruction of the RVOT induces dilatation of the cavity and subsequently dilatation of the tricuspid annulus that leads to tricuspid regurgitation , and we think that this was the cause of severe tricuspid regurgitation in our patient.
Echocardiography is the first noninvasive step for the evaluation of cardiac masses. If echocardiography cannot clearly distinguish the mass, computed tomography (CT) or cardiac magnetic resonance imaging (MRI) can be used . Cardiac MRI is superior to CT in detecting anatomic details and avoids radiation [14, 15]. Cardiac MRI with gadolinium enhancement has been found to be integral in the accurate diagnosis of cardiac masses, with an accuracy of more than 80% .
Echocardiography for our patient gave us a valuable information regarding the mass and its effect on the chambers and valves of the heart but we cannot differentiate whether is it a tumor or a thrombus. So, a cardiac MRI was requested.
Contrast enhancement in early dynamic and delayed gadolinium images in cardiac MRI is very useful in differentiating myxomas from a non-enhancing thrombus [15, 16]. In our patient, the mass showed no contrast enhancement suggesting thrombus formation. But, considering the huge size of the mass (9 × 4.6 × 3.7 cm) with the absence of symptoms and signs of pulmonary embolism, the age of the patient (15 years), and the absence of diseases that may cause a hypercoagulability state, the thrombus was less likely and the mass was likely a primary cardiac tumor. Also, the presence of manifestations of congestive heart failure and severe tricuspid regurgitation that need tricuspid repair encouraged us to decide on surgical intervention to excise the mass and repair the tricuspid valve.
On gross examination, the excised mass had a gelatinous consistency with hemorrhagic areas. Pathological examination revealed that the excised mass was a cardiac myxoma with extensive old hemorrhage inside it. We believe that the presence of extensive old hemorrhage in the myxoma was the cause of the absence of contrast enhancement in the MRI images. Katiyar et al.  reported a case of myxoma in RVOT with no enhancement on post-contrast scan subjected to contrast-enhanced computed tomography (CT) and on delayed post-gadolinium sequences in cardiac MRI, and enhancement occurred only at the site of attachment and at the thin rim of the peripheral fibrous cap. They attributed this to the central thrombotic component of the myxoma.
The approaches for resection of right ventricular masses are right atriotomy, right ventriculoctomy, and pulmonary arteriotomy [9, 12, 18]. As there was severe tricuspid regurgitation, right atriotomy was mandatory for tricuspid repair, and as we found that excision and extraction of the huge mass through the tricuspid valve could be hazardous, right ventriculotomy was done and the mass was excised and extracted through it without any complications.