Cystic Tumor of the Atrioventricular Node: A Rare and Potentially Fatal Condition

Authors

Lona Ernst Rizkallah, University of LynchburgFollow

Specialty

Cardiothoracic Surgery

Advisor

Dr. Nancy Reid

Abstract

Case Study:

Cystic tumors of the atrioventricular node (AV) are a particularly rare and benign primary cardiac tumor, comprising <3% of all cardiac tumors. Located in the triangle of Koch in the AV nodal region of the interatrial septum, these tumors, if left undiscovered, can eventually cause complete heart block or other fatal ventricular arrhythmias. Furthermore, atrioventricular cystic tumors are the smallest of all cardiac tumors to cause sudden death. These lesions are thought to be congenital and arise during embryogenesis of the heart. Predominantly found in women, and a vast majority of patients are asymptomatic. How these tumors are diagnosed varies; however, many are unfortunately diagnosed post-mortem. There are few case reports of antemortem diagnosis and resection. Here, we report a 47-year-old woman who presented to the hospital with dyspnea and palpitations. An electrocardiogram (ECG) on admission was unremarkable; however, a transthoracic echocardiogram revealed concern for a 2cm fixed mass within the interatrial septum at the base of the tricuspid valve. In addition, a cardiac magnetic resonance imaging (MRI) study validated a well-circumscribed cyst-like mass arising from the interatrial septal wall. Complete surgical resection of the tumor was accomplished; however, due to the extensive excision margins and concern for complete heart block, a permanent pacemaker was inserted at the time of surgery. Subsequently, there was also involvement of the posterior mitral valve leaflet necessitating mitral valve replacement. The pathology confirmed the diagnosis of a cystic tumor of the atrioventricular node. The management of these patients is still up for debate as no clear guidelines exist. One year postoperatively, there has been no evidence for recurrence.

Recommended Citation

Ernst Rizkallah L. Cystic Tumor of the Atrioventricular Node: A Rare and Potentially Fatal Condition. University of Lynchburg DMSc Doctoral Project Assignment Repository. 2022; 4(4).