Idiopathic Organized Thrombus of the Tricuspid Valve Mimicking Valvular Tumor

A 71-year-old man was admitted to our unit for unstable angina. He was an ex-smoker with moderate chronic obstructive pulmonary disease and varicose veins in the inferior limbs. The electrocardiogram showed left bundle branch block. Coronary angiography showed critical coronary artery stenoses of the left main, left circumflex, and first diagonal branch, and subocclusion of the left anterior descending coronary artery. Right coronary angiography revealed a mobile, ovoid vascular mass, with a shape resembling that of a cuttlefish. Tiny branches of the mass arose from the proximal portion of the main vessel, and the mass appeared to be densely and finely vascularized (Fig. 1). Right heart pressures and saturations were within normal limits. Transesophageal echocardiography showed that the mass originated from the septal leaflet of the tricuspid valve.

Fig. 1 Right coronary angiograms show a mobile, ovoid, highly vascular mass (arrows). Diastolic (A) and systolic (B) images show the mobility of the tumor.

Real-time motion image is available at texasheartinstitute.org/paolillo312.html. Contrast injection of the right coronary artery shows the dense opacification and vascularity of the tricuspid valve mass lesion.

During coronary artery bypass surgery, we explored the right atrium. A mass, 2.5 × 0.8 × 0.5 cm in size, was found on the atrial face of the tricuspid septal leaflet. The mass was soft, reddish, and sessile, with a broad base and a smooth surface (Fig. 2). The mass was completely excised with its base of implantation, and the leaflet was repaired. The postoperative period was uneventful.

Fig. 2 Gross specimen shows the broad-based attachment (scale: centimeters).

Comment

The tricuspid valve is an extremely rare location for cardiac tumors, most of which are myxomas in the adult population. Fibroelastomas, sarcomas, and metastatic tumors are even less frequently reported.^1,2 We found only 1 report in the medical literature of an organized thrombus attached to the tricuspid valve.³ In that patient, the thrombus was implanted over a pouch of the tricuspid valve, which covered a ventricular septal defect. Nonetheless, angiographic evidence of a highly vascularized cardiac mass usually points to a diagnosis of myxoma or other tumor.⁴ Therefore, in our patient, surgical removal of the mass was deemed necessary at the time of coronary artery bypass surgery, both for functional and for diagnostic reasons.

No coagulative disorder or pulmonary embolism was found in our patient. A computed tomographic scan of the entire abdomen demonstrated no thrombus along the inferior vena cava or its tributaries. The echo-Doppler scan of the legs showed organized thrombi in the veins of both calves, which supported our diagnosis of organized thrombus. The most likely origin of the thrombus was the migration of a deep-vein thrombus. The reason for the attachment of a migrating thrombus to the tricuspid valve is unclear. The presence of rich vascularization suggests that this was on old clot. The possibility that this was originally a bacterial endocarditis vegetation cannot be ruled out.

Acknowledgments

We wish to thank Drs. Sergio Coverlizza, Gianni Passarino, and Paola Burlo for their critical evaluation of the specimen, and Dr. Paolo Angelini for his helpful revision of the paper.