Cardiac myxoma: its origin and tumor characteristics.

Cardiac myxoma is most common among primary cardiac tumors, and its origin and tumor characteristics have been gradually elucidated by recent advances in molecular biology. Prichard's structure in the interatrial septum which was reported to be a candidate for the origin of cardiac myxoma, was revealed to be age-related changes. In hereditary cardiac myxoma "Carney complex", chromosomal abnormalities involving chromosomes 2p, 12 and 17q have been reported, however, no genetic abnormalities of these locus were found in the development of sporadic cases. Cardiac myxoma has multiple differentiating potentials, and recently various amounts of cardiomyocyte-specific transcription factor genes were identified. This indicates that cardiac myxoma might arise from mesenchymal cardiomyocyte progenitor cells. Various cytokines and growth factors such as vascular endothelial growth factor, basic fibroblast growth factor, monocyte chemotactic protein-1 and interleukin-6 were involved in tumor growth and angiogenesis. Although cardiac myxoma usually presents as a benign neoplasm, reports suggesting its malignancy, including recurrence of the tumor, locally invasive myxoma, extension from the heart, and distant metastasis are increasing. These genetic and molecular approaches to cardiac myxoma may prompt the development of therapeutic modalities for treatment of malignancies and cardiac cell regeneration.