Papillary fibroelastoma in the left ventricular outflow tract.

We report a case of a papillary fibroelastoma originating from the left ventricular endocardium in the outflow tract which was discovered by echocardiography in an asymptomatic patient. Two echocardiographic features were observed: (1) the tumor surface was smooth, and characteristic papillary formation was not detected; and (2) the outline of the mass was clearly defined as a dense echo, with the central, radiolucent, portion surrounded by a highly refractive linear echo at the level of the maximum diameter of the mass. The excised tumor was covered with a gelatinous substance that masked multiple papillae on the surface, but its echolucent center could not be explained by the pathology of the tumor which was solid centrally. Our case indicates that a papillary fibroelastoma may sometimes show echocardiographic findings similar to those of a myxoma, although other investigators have not noted the smooth surface and the echolucent center makes it indistinguishable from a myxoma. Thus, in some cases, it is difficult to distinguish papillary fibroelastoma from myxoma by echocardiography.