Left Atrial Fibroma in Gardner Syndrome
Real-Time 3-Dimensional Transesophageal Echo Imaging
A 72-year-old man with a history of hypertension and hyperlipidemia was referred for bradycardia and ectopic atrial rhythm on his ECG. His past medical history was remarkable for recurrent multiple colonic adenomatous polyps, multiple subcutaneous lipomas, seborrheic keratoses, an atrophic left kidney from retroperitoneal fibrosis, and left Bell palsy. He had a family history of colon polyps in his brother and a benign cecal mass in his son. Conventional 2-dimensional transthoracic and transesophageal echocardiograms (TEE) with contrast revealed a left atrial (LA) mass (4.0×3.7 cm2) attached to the atrial septum (Figure 1). Cardiac computed tomography suggested a LA mass encroaching toward the entrance of the right pulmonary veins with nearly total obstruction (Figure 2). A coronary angiogram showed neither significant coronary arterial stenosis nor feeding arteries for the mass. The patient was referred to a cardiac surgeon with a presumptive diagnosis of LA myxoma; however, intraoperative TEE and surgical inspection revealed a large and hard mass between the right superior and inferior pulmonary veins that did not impinge on their inflows, involving the posterior and superior LA walls, atrial septum, and the right atrial wall. Multiple echo-guided biopsies of the mass confirmed the mass to be a benign cardiac fibroma (Figure 3). Given the absence of symptoms or hemodynamic harm, a complete resection and reconstruction of the atrial walls was deemed too radical. Hence, total excision of the mass was not performed. A 6-month follow-up TEE performed using an x7–2t transducer on an iE33 ultrasound machine (Philips Medical Systems, Andover, Mass) with multiplane 2-dimensional, Doppler, and real-time (RT) 3-dimensional (3D) echo demonstrated no significant change in the fibroma size and revealed a broad base attachment to the superior limbus of the atrial septum adjoining the posterior wall of the LA with an independent motion (Figure 4 and online-only Data Supplement Movie I). Multiple calcific foci were noted within the mass (Figure 5). The relationship of the mass to the surrounding structures is shown in Figure 6. No compression of or impingement on the blood flow in the superior vena cava or right pulmonary veins was seen (Figure 7; online-only Data Supplement Movies II and III).
Our case fits the well-described Gardner syndrome (GS). GS was first described in 19621 as kindred with familial adenomatous polyposis associated with extracolonic growths, including osteomas, epidermoid cysts, and fibromas. It is caused by mutation in the adenomatous polyposis coli gene. Many of the different extracolonic lesions correlate with mutations at specific locations of the adenomatous polyposis coli gene.2 Genetic screening is not always helpful unless it is positive in the index case. However, clinical features play an important role in diagnosis of GS. Among the numerous extracolonic manifestations, Gardner fibroma has been reported near the spine, head, neck, extremities, chest, and abdomen.3 To our knowledge, this is the first report of a biopsy-proven cardiac fibroma associated with GS. No recommendation of whole-body tumor surveillance has been made in GS, but this case shows that the fibromatosis can affect the heart. Generally, cardiac fibromas are solitary and, unlike this one, occur exclusively within the ventricle or interventricular septum,4 growing slowly, gradually replacing the myocardium and protruding into the cavity of the heart. In this case, RT3D TEE offered better delineation of the spatial relationship of the mobile mass with the adjacent structures without postprocessing, and Echo Doppler provided additional hemodynamic information of the patency of the pulmonary veins. The characteristic inner calcific foci of the fibroma were well defined with multiple 3D anatomic planes. With these potential advantages, RT3D echo techniques should be included in any cardiac mass evaluation and follow-up.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/118/20/e692/DC1.