[Cardiac myxoma: biological features, morphology, differential diagnosis].

Cardiac myxoma in its morphology is a typical benign tumor, meanwhile, the fact of its localization in the heart chamber, directly in the constant blood flow, largely determines the clinical behavior of this neoplasm, which is often manifested by the development of characteristics that formally determine the aggressive and even malignant nature of the course. Accordingly, the malignancy of cardiac myxoma is determined more by its clinical behavior (recurrence, multifocality of the lesion, the presence of mechanisms of spread similar to metastasis) rather than by its histological picture. In the structure of primary benign tumors of the heart, myxoma occupies a dominant position and its incidence is up to 85%. According to some authors, the tumor develops from multipotent mesenchymal stem cells of the endocardium, mainly in the area of the fossa ovale, while according to others the histogenesis of the tumor remains unclear. The obligate morphology element is the myxoma cell. The presence of so-called "ring" structures is special, regular and highly specific, and Gamna - Gandy bodies, foci of calcification and superficial thrombosis are considered characteristic secondary destructive morphological signs. The review describes the morphology features, specific clinical manifestations, immunohistochemical parameters of cardiac myxoma, and presents information available in the literature on the mechanisms of tumor spread (metastasis).