1. Recurrent Atrioventricular Groove Intramuscular Arteriovenous Malformation 
Patrick O. Myers, MD, Tal Geva, MD, Harry Kozakewich, MD, Christopher W. Baird, MD, Karen K. Stout, MD, Pedro J. del Nido, MD 
The Annals of Thoracic Surgery 
Volume 94, Issue 1, Pages (July 2012)
DOI: /j.athoracsur
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Preoperative imaging. (A) Echocardiogram from the apical 4-chamber view showing a large tumor (arrow) emanating from the right atrial aspect of the atrioventricular (AV) groove abutting the tricuspid valve leaflet (TV). (B) Echocardiographic parasternal short-axis view with color Doppler showing flow signal within the tumor (arrowhead) as well as a small fistula to the right atrium (RA) (arrow). (C) Fluorodeoxyglucose positron emission tomography showing no tumor uptake (arrow). (D) MRI cine steady-state free precession image in the 4-chamber plane showing extension of the tumor onto the anterior leaflet of the tricuspid valve (arrow). (E) T2-weighted turbo spin echo MRI showing hyperintense signal (arrow) within the tumor along with areas of signal voids consistent with blood vessels. (F) Late gadolinium enhancement of the tumor (arrow) on myocardial delayed enhancement imaging suggestive of a fibrous element within the tumor. (LA = left atrium; LV= left ventricle; RV = right ventricle.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Selective right coronary angiography shows a dilatated vessel with multiple feeding vessels into the tumor (T).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Intraoperative view of tumor specimen. (A) Surgeon's view. Right coronary artery (RCA) is skeletonized from the atrioventricular (AV) groove. Right atrium (RA) is opened, showing the tumor involving the AV groove and the tricuspid valve (TV). (B) Surgical specimen in the same orientation. (C) Surgical view after resection of tumor. (AL = anterior leaflet; RV = right ventricle.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Histologic features. (A) Hematoxylin and eosin stains, original magnification ×2, showing subendocardial atrial mass consisting of poorly defined vascular nodules and dispersed larger channels. (B) Hematoxylin and eosin stains, original magnification ×400, showing small vessel component has plump endothelium and several layers of pericytes. (C) Hematoxylin and eosin stains, original magnification ×40, showing epicardial artery (left upper aspect) is transitioning to an abnormal vessel with loss of internal elastic lamina and smooth muscle and accompanied by intimal thickening. (D) Hematoxylin and eosin stains, original magnification ×100, showing cluster of abnormal veins.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions