Among congenital heart tumors reported, there are mainly rhabdomyomas and less frequently fibromas. The incidence of primary cardiac tumors in children has been reported to be 0.03–0.32%, with fibromas accounting for 25%. Approximately 70% of primary cardiac tumors are benign with a morbidity rate of around 0.27 to 0.8% [1–4]. Cardiac fibromas normally develop from the residing fibroblasts or myofibroblasts of the heart. Cardiac Fibromas are the most common condition to cause clinically significant arrhythmias even though they are pathologically benign. The presenting symptoms include arrhythmias (32%), murmurs (20%) and abnormal chest radiographs (20%) depending on the size and location of the tumor [5]. The diagnosis of cardiac fibroma does not solely depends on physical examination, X-ray, echocardiogram, computed tomography and cardiac-magnetic resonance imaging. Biopsy should also be done for confirmation [5, 6]. However, the gradually growing fibromas make it difficult to diagnose during the early stages of the condition, as the patient would remain asymptomatic, until later, the patient may present with chest pains, conduction abnormalities and ventricular inflow/outflow tract obstructions that may affect the quality of life.

Management strategy of fibromas remain controversial. To avoid the complications, such as heart inflow/outflow tract obstructions and malignant arrhythmias, some may think that early surgical intervention is the first choice of treatment when cardiac tumors, probably fibromas, are diagnosed. If the excision of the fibroma affects the integrity of the ventricle and the arrhythmias can be managed with pharmacological agents, the surgery can be postponed until the inflow/outflow tract obstruction appears [6–8].

As the fibromas are most commonly found in the left ventricular free wall or septum, the reporting case where the fibroma occupies most of the right ventricular chamber, is a comparatively rare form. In this case, the tumor reached a dimension of 26 × 22 mm and protruded to the right ventricle causing an obvious obstruction. Surgical removal of the tumor was performed soon after admission, as there is a major risk for sudden death due to conductive tissue involvement.

Till now, right ventricular outflow tract obstruction caused by such a massive fibroma in a very young patient has never been reported. Considering that fibromas are much likely to increase in size, early resection is recommended in such patients for a successful surgical outcome and at the same time avoiding potential abnormalities and cardiovascular collapse in the later life. In addition, our experience showed that the surgical procedure to excise such a large cardiac fibroma in a 5-month-old infant is feasible and safe.