مقالات پذیرفته شده در نهمین کنگره بین المللی زیست پزشکی
The impact of rhabdomyoma tumors in children and infants in different communities
The impact of rhabdomyoma tumors in children and infants in different communities
mahyarahmadi,1,*
1. Kermanshah University of Medical Sciences
Introduction: Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10–20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT) and Magnetic Resonance Imaging (MRI) of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.
Methods: The research method in this article was documentary and based on reviewing articles related to the topic. In this regard, about 15 specialized scientific articles were selected from reliable sources and references, including Online Library, Google SAGE, and PUBMED.
Results: Rhabdomyomas are the most common pediatric cardiac tumors and may underlie some causes of sudden infant death. Important differential diagnoses for cardiac rhabdomyoma include histiocytoid cardiomyopathy, cardiac conduction system abnormalities, and other heart neoplasms.
Cardiac rhabdomyomas are defined by a constellation of gross and microscopic features which may be evident during autopsy. Rhabdomyomas present grossly as either single or multiple cardiac masses, preferentially arising in the ventricles. However, these tumors may also appear in the atria, cavoatrial junction, or epicardial surface. Smaller rhabdomyomas may not be visible grossly and instead appear only during histological studies, as in the presented case. Microscopically, rhabdomyomas are classically characterized by “spider cells” consisting of swollen myocytes with clear cytoplasm and abnormal vacuolization. Immunoperoxidase staining can also help identify rhabdomyoma histology, with neoplastic muscle tissue staining positively for myoglobin and myogenin, and negatively for S100. Both rhabdomyomas and their malignant counterparts stain positively for myoglobin and demonstrate a cytoplasmic staining pattern. S100 positivity occurs in certain sarcomas and myoepithelial tumors, and rarely occurs in rhabdomyomas. If positive in rhabdomyomas, S100 demonstrates a focal staining pattern. Myogenin stains positively in fetal striated muscle and would be present in both the rhabdomyoma and surrounding normal cardiac tissue. Interpreted alongside cellular morphology, these immunoperoxidase staining patterns strongly support a diagnosis of rhabdomyoma.
Conclusion: Cardiac tumors have a reported frequency of 0.02% and 0.04% within the pediatric population and constitute a rare cause of sudden infant death. Rhabdomyomas represent the most common primary cardiac tumors in children and possess a strong link with tuberous sclerosis. Though considered benign, rhabdomyomas may present with cardiomegaly, congestive heart failure, or sudden perinatal death depending on size and local invasion. This neoplastic striated muscle tissue can contribute to cardiac arrythmia and ultimately death. We report a case of sudden death in an infant discovered at autopsy to have a cardiac rhabdomyoma. This case illustrates the importance of analyzing multiple areas of grossly normal-appearing heart in cases of sudden infant death, as this diagnosis may have been missed had only one myocardial section been analyzed.