In this case report, we describe a rare large right ventricular fibroma with sudden chest pain in a 9 year old child. The tumor was successfully surgical removed under cardiopulmonary bypass, but there was only a small remnant of the tumor to avoid rupture of the right ventricle and injury to the tricuspid valve. Pathological examination confirmed that the tumor was fibrous borderline tumor. The patient's heart function and the size of atrium and ventricles were normal, and there was no tricuspid regurgitation at 3-months follow-up. It was reported that the age less than 17 years old at time of diagnosis are associated with a poor prognosis, the long term outcome for this children patient needs further follow-up.

Aortopulmonary window (APW) is a rare but serious congenital cardiac malformation, most patients with APW will die from congestive heart failure a few months after birth. However, in this case we presented is an extremely rare condition that consist of a type III APW and a ductus arteriosus originated left pulmonary artery. Preoperative diagnosis included echocardiography and chest computerized tomography revealed anatomical structure of the heart and great vessel clearly, cardiac catheterization indicated that the pulmonary resistances indices were 2.92 wood U⁄m^2 in LPA and 3.35 wood U⁄m^2 in RPA, Qp:Qs was 3.26. This patient underwent surgical correction at the age of 9 and successfully survived.

Cor triatriatum is a rare congenital heart malformation with different natural history which depends on the size of the aperture in the partition between the proximal and distal chambers. In classic cor triatriatum all pulmonary veins return to proximal chamber (accessory left atrium, aLA), but this case we reported with left upper pulmonary vein returned to distal chamber (true left atrium, tLA). The partition had one 5mm aperture that allowed this patient grown up to adulthood without any symptoms, but finally resorted to hospital with symptomatic atrial flutter and detected this cor triatriatum accidentally. Atrial flutter may be a long-term complication of cor triatriatum during its natural history, surgical correction of cor triatriatum and radiofrequency ablation for atrial flutter is recommended once diagnosed.

Hemangioma in heart chambers is rare, most cases with heat hemangioma without symptom. The case we presented was an extremely left ventricle hemangioma with hest pain and palpitation after exercise. The tumor was resected under cardiopulmonary bypass, histopathological analysis concluded a benign vascular tumor. Examination of the tumor revealed vascular proliferation and mucoid degeneration in matrix. Immunohistochemistry showed strong positive staining with antibodies against CD31 and CD34, which supported the vascular origin of this tumor.