Discussion
Primary malignant tumors of the heart are extremely rare, constituting
around 10% of cardiac tumors in children. Sarcomas are the most common
primary cardiac malignant tumors (95%) followed by lymphomas
[1].Angiosarcoma, rhabdomyosarcoma and undifferentiated sarcomas are
the most common sarcomas in children in the order of frequency of
occurrence [2].
Rhabdomyosarcomas are mesenchymal tumors originating from
undifferentiated striated muscle [1]. They are more common in males
[3] and show extensive and aggressive local tissue infiltration and
vessel extension [4]. Most lesions tend to be single and occur more
frequently in the left atrium but, they can involve any cardiac chamber.
Histologically, they are classified as embryonal, alveolar, pleomorphic
and other types while embryonal variety (75%) is the most common type
in pediatric population [5].Most cases of rhabdomyosarcomas are
sporadic in nature although association with familial syndromes like
LiFraumeni and Neurofibromatosis type I is not uncommon [6].They
usually present with signs and symptoms congestive heart failure, chest
pain, outflow tract obstruction, recurrent pericardial effusions,
arrhythmias, pulmonary emboli and rarely sudden death depending upon the
size and location of the tumor. Echocardiography or Computing
Tomography/MRI of the heart helps with establishing the diagnosis. Open
surgical or endomyocardial biopsy aids the histological diagnosis of the
tumor. A thorough search with CT/MRI must be made to ascertain the
metastatic spread of the lesion. Palliative debulking surgery,
chemotherapy and radiotherapy extend survival but prognosis is extremely
poor with short survival (upto 13 months) due to local infiltration and
metastasis [7]