Blood cyst of the tricuspid valve.

Blood-filled cysts of the heart valves are commonly reported at postmortem examination of infants but are rarely seen in older children and adults. These cysts appear to be benign lesions and should be removed only if they cause problems. We present the case of a patient with a tricuspid valve blood cyst that was surgically removed and then discuss the differential diagnosis and management of these cysts. When a cardiac mass has features suggestive of a blood cyst, radical resection should not be performed unless histologic confirmation of tumor is obtained.