Two-dimensional echocardiographic diagnosis of tricuspid valve noninfective endocarditis due to protein C deficiency (lesion mimicking tricuspid valve myxoma).

Noninfective endocarditis may develop on heart valves in a wide variety of clinical conditions. Various events have been cited as possible etiologic factors. These lesions are clinically important because the vegetations frequently embolize and cause arterial obstruction and tissue infarction. Previously, the diagnosis of the disease had been made only at autopsies. Only a single case has been reported to have been diagnosed clinically in childhood. We present a patient with noninfective endocarditis, urgently operated on with the presumptive echocardiographic diagnosis of tricuspid valve myxoma, whose protein C level was found to be very low. It's known that in patients with homozygous congenital protein C deficiency venous thrombosis may develop. We think that the etiologic factor of the thrombosis on the tricuspid valve in the case presented is congenital protein C deficiency. With this case study we further emphasize the specific role of two-dimensional echocardiography in the diagnosis of noninfective endocarditis and recommend that protein C deficiency be investigated as an etiologic factor.