PROTEOMICS AND IMMUNOHISTOCHEMISTRY IN ATRIAL MYXOMAS: AN INNOVATIVE STUDY

The myxoma is the most common benign tumor of the heart. It is located for the 95% in the atrium (75% left atrium, 25% right atrium)5% originates from the ventricles. It has a symptom cortege that includes dyspnea, tachycardia, dimming of the sensory, thoracic and/ or retrosternal pain and syncope. Women are more affected than men, especially after the fifth decade of life. Recurrences are present in 3% of cases and occur 4 to 8 years after the first intervention. Studying the expression of the antibodies cd 31 and cd34 we have confirmed the endothelial nature of the neoplasm. Positivity of the Vascular Endothelial Growth Factor confirmed it and enhanced expression in the recurrence tissue samples showed an angiogenic factor that stimulates the growth of the endothelial cells. Also cd44 may contribute to recurrence. Our aim is to demonstrate how the overexpression of the VEGF in recurrences respect of the primitive mixoma, may involve the use of a patch soaked in anti-VEGF in the place where the tumor has been resected to avoid the recurrence of the neoplasm. With cell culture, it has been shown that neoplasia prolifera in soil enriched with VEGF, instead cell growth is inhibited and completely blocked by adding to the soil a VEGF antagonist. The immunohistochemical positivity of CD44, a mesenchymal stem cell marker, has demonstrated the presence of a stem-like subpopulation responsible for tumor initiation, maintenance and progression. This cells resided in the mucopolysaccharide-rich matrix of myxoma. The pluripotency of this population of cells also was validated by cardiomyocytes and smooth muscle cells differentiation in vitro. So our results indicate that primary cardiac myxoma may arise from mesenchymal stem cells