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Septal Cystic Mass in the Right Atrium: Echocardiographic Evaluation
Septal Cystic Mass in the Right Atrium: Echocardiographic Evaluation Saskia Ritter, MD, Lloyd Y. Tani, MD, Ronald W. Day, MD, and L. LuAnn Minich, MD, Salt Lake City, Utah
Right atrial masses rarely are seen in children and are usually benign. Clinical manifestations mainly depend on the location of the mass and whether it alters blood flow. This report describes the clinical course, echocardiographic findings, path-
Echocardiography is particularly well suited for the
imaging of intracardiac masses.1-4 This is especially true in infants and young children, but experience is limited because masses are unusual in this population.5 We used echocardiography to diagnose and follow an unusual mass located in the right atrium of an infant.
CASE REPORT A 3.6-kg, 3-week-old term infant was referred for evaluation of a murmur. She was clinically well and gaining weight appropriately. Examination revealed a mildly increased second heart sound, 2/6 systolic ejection murmur at the left upper sternal border and a mid-diastolic rumble at the apex, and mild hepatomegaly. Oxygen saturations were 90% to 94% in room air. The patient’s electrocardiogram showed first-degree heart block, a superior counterclockwise frontal plane QRS axis, right atrial enlargement, and right ventricular hypertrophy. A chest x-ray film showed moderate cardiomegaly and increased pulmonary blood flow. A complete 2-dimensional echocardiogram showed a primum atrial septal defect and 2 ventricular septal defects (1 perimembranous and 1 midmuscular just below the moderator band). In addition, a large septated mass was located in the posteroinferior right atrium adjacent to the interatrial septum (Figure 1).The mass measured 25 × 15 mm and, except for the septa, was echo-free suggesting that it was fluid-filled.
From the Department of Pediatrics, Primary Children’s Medical Center, and the University of Utah, Salt Lake City, Utah. Reprint requests: L. LuAnn Minich, MD, Primary Children’s Medical Center, 100 North Medical Center Drive, Suite 1500, Salt Lake City, UT 84113. Copyright © 1999 by the American Society of Echocardiography. 0894-7317/99 $8.00 + 0 27/4/97387
ology, and serial follow-up of an unusual cystic mass with a mixture of tissue common to the atrioventricular septum located in the posteroinferior right atrium. (J Am Soc Echocardiogr 1999; 12:331-4.)
The mass did not obstruct flow into or out of the right atrium. Because of cardiomegaly, anticongestive therapy with digoxin and diuretics was started with close follow-up for changes in clinical status. Serial echocardiograms were performed to observe any increase in size or change in the flow patterns in or around the mass. At 6 weeks of age, Doppler echocardiography showed a systolic jet (2 m/s) from the posteromedial left ventricular outflow tract into the left lateral compartment of the cyst. Magnetic resonance imaging performed around this time confirmed the fluid motion into the lesion on multiple images. At 6 months of age, the left ventricular to cyst flow was no longer detected, but a systolic jet (3.3 m/s) was seen from the right ventricle into the cyst. At 9 months of age, no flow was detected from either ventricle into the cyst, and the capsule was noted to be thicker and more echogenic. For all serial echocardiographic examinations, the cyst size remained stable and did not obstruct flow. During this time, the child continued to thrive. At 15 months of age, she underwent elective surgical repair consisting of closure of both the primum atrial septal defect and both the perimembranous and the midmuscular ventricular septal defects. A septated cyst located on the inferior wall of the right atrium was opened and drained green-yellow fluid. No communications were identified between the cyst cavity and the heart. The cyst was marsupialized to allow drainage and prevent reaccumulation. Samples of the tissue and cyst contents were sent to the pathology laboratory for analysis. The pathologic examination revealed small amounts of neural tissue, muscular arteries, small veins, and a small amount of myocardium. No epithelial or mesothelial tissue was identified. The cystic fluid showed cellular debris, proteinaceous material, and cellular components of red and white blood cells, but no atypical cells or organisms. Because all the identified tissue could occur in the atrioventricular septum near the atrioventricular valve, in the
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Figure 1 Apical 4-chamber view at the level of the atrioventricular valves demonstrating the septated mass. Note its position in the posteroinferior right atrium. RA, Right atrium; LA, left atrium.
Figure 2 Apical 4-chamber view (similar to Figure 1) 2 years after surgical removal of the mass. RA, Right atrium; LA, left atrium.
absence of epithelial or mesothelial elements the lesion was considered a benign cystic atrioventricular tumor. Two years after surgery, the patient was asymptomatic. Echocardiograms showed no residual shunts and no recurrence of the cystic lesion (Figure 2).
DISCUSSION Right atrial masses are rare in children, and the differential diagnosis includes bacterial endocarditis, atrial thrombi, atrial septal aneurysm, and benign,
Journal of the American Society of Echocardiography Volume 12 Number 5
A
Ritter et al 333
B
Figure 3 Schematic representation of the theoretic development of the septated cystic mass described in this report. A, The area involved when an embryologic defect leads to an atrioventricular septal defect is shown. B, The cyst that potentially developed outward from this area is shown. RA, Right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle.
malignant or metastatic cardiac tumors.5-9 Twodimensional echocardiography is ideal for identifying the mass and for providing serial assessments of its size, location, characteristics, extension, and recurrence after removal. Doppler echocardiography allows evaluation of the flow patterns into and around the mass. Cystic intracardiac masses that may show a typical echocardiographic appearance include myxomas, teratomas, blood cysts or clots, and hamartomas. Most myxomas have a short, broad-based attachment and are pedunculated. Teratomas are usually pearshaped, with a smooth, lobulated surface. Benign cysts are usually fluid filled and generally show septa and central spaces without returning echoes. All cardiac masses may change in size and appearance over time.1 Although the indications for surgical intervention include progressive increase in mass size, obstruction to flow, or embolization,10 the indication for surgery in this patient was closure of the cardiac defects. The child remained asymptomatic and had a mass that did not change in appearance over time, which allowed a period of close observation. It is interesting that, at different times, flow could be seen entering the cyst from the left and right ventricles. This finding is consistent with the cyst’s location and with its composition of cells comprising the atrioventricular canal. Improper partitioning of the embryonic atrioventricular canal results in the characteristic 5-leaflet atrioventricular valve and the
potential for both atrial and ventricular level shunting.11 Left ventricular to right atrial shunting may occur through a “cleft”between the anterior and posterior leaflets of the left atrioventricular valve. Here, the cyst was lying in this area, so the shunt was directed into it rather than into the right atrium. Similarly, right atrioventricular valve regurgitation could be directed into the mass (Figure 3). With growth or thickening of the mass capsule (as occurred in this patient), these communications may have closed spontaneously. Thus 2-dimensional and Doppler echocardiography provided an accurate noninvasive method for the detection and characterization of an unusual right atrial cyst in a patient with an atrioventricular canal defect. Serial studies allowed evaluation of potential anatomic and physiologic progression, guiding the timing of surgery.1 Echocardiography also has been useful for follow-up assessements and has shown no recurrence of the cyst. REFERENCES 1. Marx GR, Bierman FZ, Matthews E, Williams R. Twodimensional echocardiographic diagnosis of intracardiac masses in infancy. J Am Coll Cardiol 1984;3:827-32. 2. Riggs T, Paul MH, DeLeon S, Ilbawi M. Two dimensional echocardiography in evaluation of right atrial masses: five cases in pediatric patients. Am J Cardiol 1981;48:961-6. 3. Martin RP. Clinical utility of two-dimensional echocardiography in the detection of intracardiac mass lesions. Adv Cardiol 1980;27:58-70.
334 Ritter et al
4. Hickey AJ, Wolfers J, Wilcken DEL. Cardiac tumour: an echocardiographic diagnosis. Med J Aust 1982;2:267-9. 5. McAllister HA Jr. Primary tumors and cysts of the heart and pericardium. Curr Probl Cardiol 1979;4:1-51. 6. Smith AJ, Panidis IP, Berger S, Gonzales R. Large atrial septal aneurysm mimicking a cystic right atrial mass. Am Heart J 1990;120:714-6. 7. Yeoh JK, Appelbe AF, Martin RP. Atrial septal aneurysm mimicking a right atrial mass on transesophageal echocardiography. Am J Cardiol 1991;68:827-8. 8. Chan HSL, Sonley MJ, Moes CAF, Daneman A, Smith CR, Martin DJ. Primary and secondary tumors of childhood
Journal of the American Society of Echocardiography May 1999
involving the heart, pericardium, and great vessels. Cancer 1985;56:825-36. 9. Malaterre HR, Kallee K, Deharo JC, Djiane P. Right- and left-sided interatrial septal aneurysm mimicking atrial tumor and stroke. J Am Soc Echocardiogr 1998;11:829-31. 10. Skillington PD, Brawn WJ, Edis BD, Menahem S, Venables AW, Goh TH, Mee RBB. Surgical excision of primary cardiac tumors in infancy. Aust N Z J Surg 1987;57:599-604. 11. Penkoske PA, Neches WH, Anderson RH, Zuberbuhler JR. Further information on the morphology of atrioventricular septal defect. J Thorac Cardiovasc Surg 1985;90: 611-22.
Bound volumes available to subscribers Bound volumes of the Journal of the American Society of Echocardiography are available to subscribers (only) for the 1999 issues from the Publisher at a cost of $95.00 for domestic, $115.56 Canadian, and $108.00 for international subscribers for Vol 12 (January-December). Shipping charges are included. Each bound volume contains a subject and author index, and all advertising is removed. The binding is durable buckram with the Journal name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Mosby, Inc, Subscription Services, 11830 Westline Industrial Dr, St Louis, MO 63146-3318, USA; telephone (800)325-4177, ext 4351, or (314)453-4351. Subscriptions must be in force to quality. Bound volumes are not available in place of a regular Journal subscription.
Right atrial masses rarely are seen in children and are usually benign. Clinical manifestations mainly depend on the location of the mass and whether it alters blood flow. This report describes the clinical course, echocardiographic findings, path-
Echocardiography is particularly well suited for the
imaging of intracardiac masses.1-4 This is especially true in infants and young children, but experience is limited because masses are unusual in this population.5 We used echocardiography to diagnose and follow an unusual mass located in the right atrium of an infant.
CASE REPORT A 3.6-kg, 3-week-old term infant was referred for evaluation of a murmur. She was clinically well and gaining weight appropriately. Examination revealed a mildly increased second heart sound, 2/6 systolic ejection murmur at the left upper sternal border and a mid-diastolic rumble at the apex, and mild hepatomegaly. Oxygen saturations were 90% to 94% in room air. The patient’s electrocardiogram showed first-degree heart block, a superior counterclockwise frontal plane QRS axis, right atrial enlargement, and right ventricular hypertrophy. A chest x-ray film showed moderate cardiomegaly and increased pulmonary blood flow. A complete 2-dimensional echocardiogram showed a primum atrial septal defect and 2 ventricular septal defects (1 perimembranous and 1 midmuscular just below the moderator band). In addition, a large septated mass was located in the posteroinferior right atrium adjacent to the interatrial septum (Figure 1).The mass measured 25 × 15 mm and, except for the septa, was echo-free suggesting that it was fluid-filled.
From the Department of Pediatrics, Primary Children’s Medical Center, and the University of Utah, Salt Lake City, Utah. Reprint requests: L. LuAnn Minich, MD, Primary Children’s Medical Center, 100 North Medical Center Drive, Suite 1500, Salt Lake City, UT 84113. Copyright © 1999 by the American Society of Echocardiography. 0894-7317/99 $8.00 + 0 27/4/97387
ology, and serial follow-up of an unusual cystic mass with a mixture of tissue common to the atrioventricular septum located in the posteroinferior right atrium. (J Am Soc Echocardiogr 1999; 12:331-4.)
The mass did not obstruct flow into or out of the right atrium. Because of cardiomegaly, anticongestive therapy with digoxin and diuretics was started with close follow-up for changes in clinical status. Serial echocardiograms were performed to observe any increase in size or change in the flow patterns in or around the mass. At 6 weeks of age, Doppler echocardiography showed a systolic jet (2 m/s) from the posteromedial left ventricular outflow tract into the left lateral compartment of the cyst. Magnetic resonance imaging performed around this time confirmed the fluid motion into the lesion on multiple images. At 6 months of age, the left ventricular to cyst flow was no longer detected, but a systolic jet (3.3 m/s) was seen from the right ventricle into the cyst. At 9 months of age, no flow was detected from either ventricle into the cyst, and the capsule was noted to be thicker and more echogenic. For all serial echocardiographic examinations, the cyst size remained stable and did not obstruct flow. During this time, the child continued to thrive. At 15 months of age, she underwent elective surgical repair consisting of closure of both the primum atrial septal defect and both the perimembranous and the midmuscular ventricular septal defects. A septated cyst located on the inferior wall of the right atrium was opened and drained green-yellow fluid. No communications were identified between the cyst cavity and the heart. The cyst was marsupialized to allow drainage and prevent reaccumulation. Samples of the tissue and cyst contents were sent to the pathology laboratory for analysis. The pathologic examination revealed small amounts of neural tissue, muscular arteries, small veins, and a small amount of myocardium. No epithelial or mesothelial tissue was identified. The cystic fluid showed cellular debris, proteinaceous material, and cellular components of red and white blood cells, but no atypical cells or organisms. Because all the identified tissue could occur in the atrioventricular septum near the atrioventricular valve, in the
331
332 Ritter et al
Journal of the American Society of Echocardiography May 1999
Figure 1 Apical 4-chamber view at the level of the atrioventricular valves demonstrating the septated mass. Note its position in the posteroinferior right atrium. RA, Right atrium; LA, left atrium.
Figure 2 Apical 4-chamber view (similar to Figure 1) 2 years after surgical removal of the mass. RA, Right atrium; LA, left atrium.
absence of epithelial or mesothelial elements the lesion was considered a benign cystic atrioventricular tumor. Two years after surgery, the patient was asymptomatic. Echocardiograms showed no residual shunts and no recurrence of the cystic lesion (Figure 2).
DISCUSSION Right atrial masses are rare in children, and the differential diagnosis includes bacterial endocarditis, atrial thrombi, atrial septal aneurysm, and benign,
Journal of the American Society of Echocardiography Volume 12 Number 5
A
Ritter et al 333
B
Figure 3 Schematic representation of the theoretic development of the septated cystic mass described in this report. A, The area involved when an embryologic defect leads to an atrioventricular septal defect is shown. B, The cyst that potentially developed outward from this area is shown. RA, Right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle.
malignant or metastatic cardiac tumors.5-9 Twodimensional echocardiography is ideal for identifying the mass and for providing serial assessments of its size, location, characteristics, extension, and recurrence after removal. Doppler echocardiography allows evaluation of the flow patterns into and around the mass. Cystic intracardiac masses that may show a typical echocardiographic appearance include myxomas, teratomas, blood cysts or clots, and hamartomas. Most myxomas have a short, broad-based attachment and are pedunculated. Teratomas are usually pearshaped, with a smooth, lobulated surface. Benign cysts are usually fluid filled and generally show septa and central spaces without returning echoes. All cardiac masses may change in size and appearance over time.1 Although the indications for surgical intervention include progressive increase in mass size, obstruction to flow, or embolization,10 the indication for surgery in this patient was closure of the cardiac defects. The child remained asymptomatic and had a mass that did not change in appearance over time, which allowed a period of close observation. It is interesting that, at different times, flow could be seen entering the cyst from the left and right ventricles. This finding is consistent with the cyst’s location and with its composition of cells comprising the atrioventricular canal. Improper partitioning of the embryonic atrioventricular canal results in the characteristic 5-leaflet atrioventricular valve and the
potential for both atrial and ventricular level shunting.11 Left ventricular to right atrial shunting may occur through a “cleft”between the anterior and posterior leaflets of the left atrioventricular valve. Here, the cyst was lying in this area, so the shunt was directed into it rather than into the right atrium. Similarly, right atrioventricular valve regurgitation could be directed into the mass (Figure 3). With growth or thickening of the mass capsule (as occurred in this patient), these communications may have closed spontaneously. Thus 2-dimensional and Doppler echocardiography provided an accurate noninvasive method for the detection and characterization of an unusual right atrial cyst in a patient with an atrioventricular canal defect. Serial studies allowed evaluation of potential anatomic and physiologic progression, guiding the timing of surgery.1 Echocardiography also has been useful for follow-up assessements and has shown no recurrence of the cyst. REFERENCES 1. Marx GR, Bierman FZ, Matthews E, Williams R. Twodimensional echocardiographic diagnosis of intracardiac masses in infancy. J Am Coll Cardiol 1984;3:827-32. 2. Riggs T, Paul MH, DeLeon S, Ilbawi M. Two dimensional echocardiography in evaluation of right atrial masses: five cases in pediatric patients. Am J Cardiol 1981;48:961-6. 3. Martin RP. Clinical utility of two-dimensional echocardiography in the detection of intracardiac mass lesions. Adv Cardiol 1980;27:58-70.
334 Ritter et al
4. Hickey AJ, Wolfers J, Wilcken DEL. Cardiac tumour: an echocardiographic diagnosis. Med J Aust 1982;2:267-9. 5. McAllister HA Jr. Primary tumors and cysts of the heart and pericardium. Curr Probl Cardiol 1979;4:1-51. 6. Smith AJ, Panidis IP, Berger S, Gonzales R. Large atrial septal aneurysm mimicking a cystic right atrial mass. Am Heart J 1990;120:714-6. 7. Yeoh JK, Appelbe AF, Martin RP. Atrial septal aneurysm mimicking a right atrial mass on transesophageal echocardiography. Am J Cardiol 1991;68:827-8. 8. Chan HSL, Sonley MJ, Moes CAF, Daneman A, Smith CR, Martin DJ. Primary and secondary tumors of childhood
Journal of the American Society of Echocardiography May 1999
involving the heart, pericardium, and great vessels. Cancer 1985;56:825-36. 9. Malaterre HR, Kallee K, Deharo JC, Djiane P. Right- and left-sided interatrial septal aneurysm mimicking atrial tumor and stroke. J Am Soc Echocardiogr 1998;11:829-31. 10. Skillington PD, Brawn WJ, Edis BD, Menahem S, Venables AW, Goh TH, Mee RBB. Surgical excision of primary cardiac tumors in infancy. Aust N Z J Surg 1987;57:599-604. 11. Penkoske PA, Neches WH, Anderson RH, Zuberbuhler JR. Further information on the morphology of atrioventricular septal defect. J Thorac Cardiovasc Surg 1985;90: 611-22.
Bound volumes available to subscribers Bound volumes of the Journal of the American Society of Echocardiography are available to subscribers (only) for the 1999 issues from the Publisher at a cost of $95.00 for domestic, $115.56 Canadian, and $108.00 for international subscribers for Vol 12 (January-December). Shipping charges are included. Each bound volume contains a subject and author index, and all advertising is removed. The binding is durable buckram with the Journal name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Mosby, Inc, Subscription Services, 11830 Westline Industrial Dr, St Louis, MO 63146-3318, USA; telephone (800)325-4177, ext 4351, or (314)453-4351. Subscriptions must be in force to quality. Bound volumes are not available in place of a regular Journal subscription.