Benign lipomatous formations rank second in frequency among primary cardiac tumors. According to the degree of encapsulation, they are divided into two groups — adipose tumors and lipomatous hypertrophies of interatrial septum. Cases of lipomatosis of the heart and lipomatous hypertrophy of interatrial septum were described in scientifi c editions in years past. Interest in this pathology is related to the question: is it necessary to perform preventive surgical intervention before the appearance of clinical signs of endocardial hemodynamics disturbance? Moreover, the risk associated with surgery is much higher than the existence of a benign hyperplastic process in the anatomical structures of the heart.