Mixomas cardíacos: estudio morfológico e inmunohistoquímico de 50 biopsias

myxomas are the most frequent primary tumors of the heart. fifty cardiac biopsies of myxomas were analyzed by histopathology, in 24 of which, the immunohistochemical was done. patients (m/f: 19/31) whose ages were between second and seventh decade of life, presented varied sintomatology, were operated with the diagnosis of tumor and/or intracardiac mass. the most frequent location of myxomas was in left (86.0 %) and right (8.0 %) auricles. macrocospically, they presented gelatinous and mixoide aspect, one single case was petrified. they measured between 3 and 10 cm and 50.0 % were pediculate. to the light microscope, they were characterized by: isolated cells or forming vascular structures (94.0 %), seudopapilars (54.0 %) and pseudo glandulars (4.0 %); abundant mixoide matrix with inflammatory cells (96.0 %), hemorrhage (94.0 %), nodules of gamna-gandi (30.0 %) and calcifications (18.0 %). the immunohistochemical study revealed: positive marker in the tumorlike cells: vimentine (100.0 %), cd34 (83.0 %), actine smooth muscle (37.0 %) desmine (17.0 %). the marker for s-100 were negative and the cytoqueratine (a1/ae3) was positive in a single case with glandular differentiation. conclusions: on the base of the immunohistochemical study, we considered that evidences exist that support the mesenquimal origin of the tumor with predominant differentiation towards the endotelial line.