- Email: [email protected]
Clinical presentation and investigation of cardiac tumors
Seminars in Diagnostic Pathology (2008) 25, 65-68
Clinical presentation and investigation of cardiac tumors Claudine M. Lewis, MBBS, DM (Internal Medicine) From the Division of Cardiology, Department of Medicine, University of Toronto, Mount Sinai Hospital, Toronto, Ontario, Canada. KEYWORDS Cardiac; Tumor; Diagnosis; Imaging
Cardiac tumors are relatively rare. Their consequences if left untreated are dire, thus requiring a prompt diagnosis. The diagnosis of a cardiac tumor may be suggested by the clinical presentation, but can seldom be made on history and physical examination alone. The diagnosis can be made with a fair degree of accuracy in most cases, by combining the clinical presentation with the known typical findings on cardiac imaging. The two-dimensional echocardiogram is the imaging modality of choice for cardiac tumors. However, owing to limitations in image quality, as well as delineating the extent of disease in suspected malignant tumors, echocardiographic diagnosis may be equivocal. Cardiac CT and MRI become important in these cases. © 2008 Elsevier Inc. All rights reserved.
Cardiac tumors represent a particular challenge in diagnosis. Low frequency of occurrence coupled with chameleon symptoms and signs that mimic more common pathologic entities add to this diagnostic challenge. The clinical scheme for classification of cardiac tumors may be based on: 1. Origin: primary versus metastatic; 2. Location: intramural versus intracavitary; and 3. Histology: benign versus malignant. Data for the incidence of primary cardiac tumors is mostly based on older autopsy studies, suggesting a prevalence of 0.001% to 0.3%.1,2 These studies also suggest that metastatic tumors are 3 to 100 times more common than primary tumors. Much of these data were compiled and reported before the use of echocardiography and before cardiac magnetic resonance imaging (MRI) and computed tomography (CT) scanning, became widespread. With the improved resolution with these imaging techniques, the diagnosis is Address reprint requests and correspondence: Claudine M. Lewis, MBBS, DM (Internal Medicine), University Of Toronto, Division of Cardiology, Department of Medicine, Mount Sinai Hospital, 600 University Avenue, Suite 1543, Toronto, ON, Canada M5G 1X5. E-mail: [email protected].
0740-2570/$ -see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1053/j.semdp.2007.12.003
now commonly made antemortem. Recent data out of China based on surgical specimens confirm this low prevalence, but challenges the previously held belief that metastatic tumors are more common.3 This may be misleading, since relatively few patients today have an autopsy performed and the statistics for the presence of metastases to the heart would likely be quite different if the heart was examined at postmortem examination. A total of 75% of all primary cardiac tumors are benign, with 75% of these being myxomas in the adult patient and rhabdomyomas in the pediatric age group (Table 1). Myxomas occur far more commonly in the left atrium but may occur in the right atrium, and a small number of cases have been reported as arising from the ventricles.4 Of the malignant cardiac tumors, sarcomas are the most common and are usually right atrial in location. Angiosarcomas are more common in adults, whereas rhabdomyosarcomas are more common in children. Malignant cardiac tumors usually originate intramurally and then extend into the pericardial space or into the cavities. Metastatic tumors may be located in the pericardial space or may be intramural or intracavitary. The pericardium is involved in up to 75% of tumors that metastasize to the heart. Their origins are varied with melanoma being the most common, followed by breast, lung, and lymphoma. In
66
Seminars in Diagnostic Pathology, Vol 25, No 1, February 2008
Table 1 Relative frequency of occurrence of primary cardiac tumors* Type Benign Myxoma Lipoma Papillary fibroelastoma Rhabdomyoma Fibroma Hemangioma Teratoma Malignant Angiosarcoma Rhabdomyosarcoma Fibrosarcoma Mesothelioma Lymphoma Leiyomosarcoma
Percent 30 10 8 6 3 2 1 8 5 3 3 2 1
*Adapted from Fiegenbaums Echocardiography (ed 6). Philadelphia, PA, Lippincott Williams and Wilkins, 2005, p 703.
an autopsy series, 10% of malignant tumors metastasized to the heart, although the presence of these metastases is often clinically unrecognized. In the pediatric age group, sources of metastatic tumors include Wilm’s tumor, neuroblastoma, malignant teratoma, and pleuropulmonary blastoma. Hematological neoplasms (leukemias and to some extent lymphomas) were in the past reported to involve the heart more frequently than solid tumors. The actual incidence of these metastases is difficult to gauge today, as the treatment of malignant tumors has changed and results improved significantly, and also, autopsy rates have declined very significantly worldwide.5
Clinical presentation The clinical presentation of cardiac tumors varies, depending on the location and whether the tumor is benign or malignant. The most frequent presenting symptom is congestive heart failure.6 Tumors are also often asymptomatic and found incidentally, at investigation, especially at echocardiography. In these cases, the tumors are usually ventricular in origin and intramural in location (see Table 2).
Congestive heart failure Congestive heart failure may occur with either atrial or ventricular tumors. Right-sided heart failure syndrome may occur if there is obstruction of inflow into either the right atrium or right ventricle. The typical symptoms of peripheral edema, ascites and hepatomegaly, may occur. Examination of the patient may reveal elevated jugular venous pressure and possibly evidence of superior vena cava obstruction. If the tumor is a sarcoma, the symptoms of right heart failure may progress rapidly. Additionally, lack of
other valvular findings should raise suspicion of a right atrial tumor.7 Left-sided heart failure symptoms may also occur if there is obstruction to inflow into the left ventricle by a left atrial tumor that may prolapse into the mitral valve. Left heart failure syndrome, with typical symptoms of dyspnoea, orthopnoea, and paroxysmal nocturnal dyspnoea, may result in these cases. Examination of these patients may reveal pulmonary congestion. Left atrial myxomas are typically mobile and pedunculated and may prolapse into the mitral valve orifice. This may result in obstruction of blood flow to the left ventricle as well as mitral regurgitation. The signs and symptoms may imitate mitral valve disease, namely dyspnoea, orthopnoea, and paroxysmal nocturnal dyspnoea. The occurrence of constitutional symptoms with mitral valve disease is less likely, and its presence should raise suspicions of a cardiac tumor. Another distinguishing feature is the uncommon occurrence of atrial fibrillation, presumably because of the absence of left atrial enlargement in patients with cardiac tumors. Additionally, the symptoms are paroxysmal and typically arise in a particular body position.
Thromboembolism Embolization of tumor fragments or thrombus from the surface of a tumor occurs frequently. Some myxomas are friable, and because they are intracavitary, they are the most frequent source of tumor emboli. Other types of tumors may occasionally embolize. Right-sided tumors may embolize to the lungs or systemically in the presence of intracardiac right-to-left shunts. Left-sided tumors embolize systemically resulting in stroke, visceral infarction, peripheral limb ischemia, and peripheral vascular aneurysms. An embolic stroke in a young person in sinus rhythm should raise the possibility of an intracardiac tumor. Multiple systemic emboli may mimic infective endocarditis or vasculitis.
Murmurs and heart sounds Systolic or diastolic murmurs may occur, particularly with murmurs in an intracavitary location. Murmurs causing obstruction of flow into the right or the left atrium may
Table 2
Clinical presentation of cardiac tumors*
Symptoms
Number
Congestive heart failure Thrombo-embolism Incidental/asymptomatic Chest discomfort Murmur Constitutional symptoms Dizziness Arrhythmia
8 (28%) 5 (17%) 6 (21%) 4 (14%) 3 (10%) 1 (3%) 1 (3%) 1 (3%)
*Adapted from Odim et al.6
Lewis
Cardiac Tumors
cause diastolic murmurs mimicking tricuspid or mitral stenosis, respectively. The S1 may be split, and there may be a tumor plop. This tumor plop occurs early in diastole and when due to a left-sided tumor is later than the opening snap of mitral stenosis and earlier than the S3. These tumors may also interfere with the valve apparatus, causing tricuspid or mitral regurgtiation.
Constitutional symptoms The presence of constitutional symptoms in a patient who may appear to have valvular abnormalities should raise the suspicion of a cardiac tumor. Weight loss, fever, arthralgias, and an elevated ESR may all occur.
Arrhythmias Intramural tumors may cause disturbances of conduction or rhythm depending on the location of the tumor. Tumors with atrial involvement or attachment, such as myxomas, sarcomas, and lipomas, may produce a wide variety of supraventricular tachyarrhythmias. This includes atrial fibrillation, atrial flutter, and ectopic atrial tachycardia. Tumors in the area of the atrioventricular node, typically angiomas and mesotheliomas, may produce conduction abnormalities such as complete heart block or asystole. Tumors within the ventricular myocardium may produce premature ventricular beats, ventricular tachycardia, ventricular fibrillation, and sudden cardiac death.
Investigation of cardiac tumors Imaging is an important tool in making a diagnosis of a cardiac tumor. As evident from the previous discussion, the clinical presentation may be quite nonspecific. The imaging modality of choice is the transthoracic echocardiogram (TTE), and where TTE is suboptimal, transesophageal echocardiography (TEE) is warranted. Cardiac CT or MRI is of no incremental value where the echocardiogram is of good quality and identifies the tumor, its exact location, and its attachments. To a lesser degree, a chest x-ray may yield some diagnostic information. Cardiac catheterization was the first method used to diagnose cardiac tumors antemortem, but is no longer used since the advent of echocardiography, cardiac CT, and MRI. Today the use of angiography is limited to special circumstances. Where good images are obtained, TTE can help make a diagnosis of cardiac myxoma with a fair degree of certainty. Typically, myxomas are located in the fossa ovalis of the interatrial septum. They are often pedunculated, with a very short stalk, which in the case of small tumors, may be nonexistent. TTE has limited use in the diagnosis of lipomas. Lipomas in the pericardial space are usually hypoechoic and have the appearance of fluid, whereas intracavitary lipomas tend to be hyperechoic. CT and MR offer
67 better diagnostic specificity in identifying fat and can thus yield an unequivocal diagnosis of lipoma. Studies have shown that the best imaging modality for a lipoma is the MRI.8 MRI is useful in verification of masses seen on TTE as well as for excluding masses when the TTE is equivocal. T1- and T2-weighted images provide detailed morphologic information. T1 gives excellent soft tissue characterization, and T2 provides superior soft tissue contrast and demonstration of fluid components. MRI allows for tissue characterization by comparing T1 and T2 values of masses to a reference tissue (fat). It is limited to the diagnosis of myxomas, fibromas, thrombi, and fatty tissue.8 Malignant primary cardiac tumors usually appear as broad-based right atrial mass(es) near the inferior vena cava (IVC), in contrast to myxomas, which almost invariably arise from the region of the fossa ovalis. Both CT and MRI are helpful in determining the degree of infiltration. As metastatic cardiac tumors affect the pericardium primarily, pericardial effusion is the most common echocardiographic finding. Renal cell carcinoma may spread along the IVC and extend into the right atrium. Both TTE and TEE are of limited value in evaluating masses in the mediastinum and pericardiac structures. CT scanning provides a high degree of soft tissue discrimination and is helpful in determining the degree of myocardial infiltration. Electron beam CT (EBCT) provides fast data acquisition rendering cardiac gating not absolutely necessary.9 Mosseaux and coworkers showed that EBCT provided additional anatomical information over TTE in patients with malignant tumors but not in those with myxomas.9 EBCT can show the extent of disease, including invasion of contiguous vessels and pulmonary metastases, better than TTE. It can also visualize neoplastic pulmonary emnboli. It also shows calcium, compared with MRI which does not show calcium, so is useful in patients with rhabdomyomas, fibromas, teratomas, myxomas, hemangiomas, and osteosarcoma. One of the major limitations of all the major current imaging modalities is their ability to accurately distinguish thrombus from benign and malignant tumors. The technique of contrast perfusion echocardiography has tried to improve the diagnostic accuracy of echocardiograms in this area. Kirkpatrick and coworkers demonstrated that malignant tumors that are more vascular than thrombus or benign tumors hyperenhance with contrast. This has been shown to be a reliable distinguishing feature.10
Conclusion Cardiac tumors are an important diagnostic entity. Recent data have demonstrated that the incidence of primary cardiac tumors has been underestimated in the past. Their protean manifestations do make the diagnosis challenging. A combination of clinical findings and appropriate imaging
68 techniques will help to clarify the diagnosis in most cases. The diagnosis is crucial as treatment in most cases is surgical. Some cases, though, will not be diagnosed with complete certainty preoperatively, owing to the limitations of the currently available imaging techniques.
References 1. Roberts WC: Primary and secondary neoplasms of the heart. Am J Cardiol 80:671-682, 1997 2. Reynan K: Frequency of primary tumors of the heart. Am J Cardiol 77:107-116, 1996 3. Yu K, Liu Y, Wang H, et al: Epidemiological and pathological characteristics of cardiac tumors: a clinical study of 242 cases. Interact Cardiovasc Thorac Surg 6:636-639, 2007
Seminars in Diagnostic Pathology, Vol 25, No 1, February 2008 4. Sarjeant JM, Butany J, Cusimano RJ: Cancer of the heart. Epidemiology and management of primary tumors and metastases. Am J Cardiovasc Drugs 3:407-421, 2003 5. Butany J, Nair V, Naseemuddin A, et al: Cardiac tumours: diagnosis and management. Lancet Oncol 6:219-228, 2005 6. Odim J, Reehal V, Laks H, et al: Surgical pathology of cardiac tumors. Two decades at an urban institution. Cardiovasc Pathol 12:267-276, 2003 7. Braunwald E: Heart Disease: A Textbook of Cardiovascular Medicine (ed 7). Philadelphia, PA, WB Saunders, 2005, pp 1731-1755 8. Hoffmann U, Globits S, Frank H: Cardiac and paracardiac masses. Current opinion on diagnostic evaluation by magnetic resonance imaging. Eur Heart J 19:553-563, 1998 9. Mousseaux E, Hernigou A, Azencot M, et al: Evaluation by electron beam computed tomography of intracardiac masses suspected by transesophageal echocardiography. Heart 76:256-263, 1996 10. Kirkpatrick JN, Wong T, Bednarz JE, et al: Differential diagnosis of cardiac masses using contrast echocardiographic perfusion imaging. J Am Coll Cardiol 43:1412-1419, 2004
Clinical presentation and investigation of cardiac tumors Claudine M. Lewis, MBBS, DM (Internal Medicine) From the Division of Cardiology, Department of Medicine, University of Toronto, Mount Sinai Hospital, Toronto, Ontario, Canada. KEYWORDS Cardiac; Tumor; Diagnosis; Imaging
Cardiac tumors are relatively rare. Their consequences if left untreated are dire, thus requiring a prompt diagnosis. The diagnosis of a cardiac tumor may be suggested by the clinical presentation, but can seldom be made on history and physical examination alone. The diagnosis can be made with a fair degree of accuracy in most cases, by combining the clinical presentation with the known typical findings on cardiac imaging. The two-dimensional echocardiogram is the imaging modality of choice for cardiac tumors. However, owing to limitations in image quality, as well as delineating the extent of disease in suspected malignant tumors, echocardiographic diagnosis may be equivocal. Cardiac CT and MRI become important in these cases. © 2008 Elsevier Inc. All rights reserved.
Cardiac tumors represent a particular challenge in diagnosis. Low frequency of occurrence coupled with chameleon symptoms and signs that mimic more common pathologic entities add to this diagnostic challenge. The clinical scheme for classification of cardiac tumors may be based on: 1. Origin: primary versus metastatic; 2. Location: intramural versus intracavitary; and 3. Histology: benign versus malignant. Data for the incidence of primary cardiac tumors is mostly based on older autopsy studies, suggesting a prevalence of 0.001% to 0.3%.1,2 These studies also suggest that metastatic tumors are 3 to 100 times more common than primary tumors. Much of these data were compiled and reported before the use of echocardiography and before cardiac magnetic resonance imaging (MRI) and computed tomography (CT) scanning, became widespread. With the improved resolution with these imaging techniques, the diagnosis is Address reprint requests and correspondence: Claudine M. Lewis, MBBS, DM (Internal Medicine), University Of Toronto, Division of Cardiology, Department of Medicine, Mount Sinai Hospital, 600 University Avenue, Suite 1543, Toronto, ON, Canada M5G 1X5. E-mail: [email protected].
0740-2570/$ -see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1053/j.semdp.2007.12.003
now commonly made antemortem. Recent data out of China based on surgical specimens confirm this low prevalence, but challenges the previously held belief that metastatic tumors are more common.3 This may be misleading, since relatively few patients today have an autopsy performed and the statistics for the presence of metastases to the heart would likely be quite different if the heart was examined at postmortem examination. A total of 75% of all primary cardiac tumors are benign, with 75% of these being myxomas in the adult patient and rhabdomyomas in the pediatric age group (Table 1). Myxomas occur far more commonly in the left atrium but may occur in the right atrium, and a small number of cases have been reported as arising from the ventricles.4 Of the malignant cardiac tumors, sarcomas are the most common and are usually right atrial in location. Angiosarcomas are more common in adults, whereas rhabdomyosarcomas are more common in children. Malignant cardiac tumors usually originate intramurally and then extend into the pericardial space or into the cavities. Metastatic tumors may be located in the pericardial space or may be intramural or intracavitary. The pericardium is involved in up to 75% of tumors that metastasize to the heart. Their origins are varied with melanoma being the most common, followed by breast, lung, and lymphoma. In
66
Seminars in Diagnostic Pathology, Vol 25, No 1, February 2008
Table 1 Relative frequency of occurrence of primary cardiac tumors* Type Benign Myxoma Lipoma Papillary fibroelastoma Rhabdomyoma Fibroma Hemangioma Teratoma Malignant Angiosarcoma Rhabdomyosarcoma Fibrosarcoma Mesothelioma Lymphoma Leiyomosarcoma
Percent 30 10 8 6 3 2 1 8 5 3 3 2 1
*Adapted from Fiegenbaums Echocardiography (ed 6). Philadelphia, PA, Lippincott Williams and Wilkins, 2005, p 703.
an autopsy series, 10% of malignant tumors metastasized to the heart, although the presence of these metastases is often clinically unrecognized. In the pediatric age group, sources of metastatic tumors include Wilm’s tumor, neuroblastoma, malignant teratoma, and pleuropulmonary blastoma. Hematological neoplasms (leukemias and to some extent lymphomas) were in the past reported to involve the heart more frequently than solid tumors. The actual incidence of these metastases is difficult to gauge today, as the treatment of malignant tumors has changed and results improved significantly, and also, autopsy rates have declined very significantly worldwide.5
Clinical presentation The clinical presentation of cardiac tumors varies, depending on the location and whether the tumor is benign or malignant. The most frequent presenting symptom is congestive heart failure.6 Tumors are also often asymptomatic and found incidentally, at investigation, especially at echocardiography. In these cases, the tumors are usually ventricular in origin and intramural in location (see Table 2).
Congestive heart failure Congestive heart failure may occur with either atrial or ventricular tumors. Right-sided heart failure syndrome may occur if there is obstruction of inflow into either the right atrium or right ventricle. The typical symptoms of peripheral edema, ascites and hepatomegaly, may occur. Examination of the patient may reveal elevated jugular venous pressure and possibly evidence of superior vena cava obstruction. If the tumor is a sarcoma, the symptoms of right heart failure may progress rapidly. Additionally, lack of
other valvular findings should raise suspicion of a right atrial tumor.7 Left-sided heart failure symptoms may also occur if there is obstruction to inflow into the left ventricle by a left atrial tumor that may prolapse into the mitral valve. Left heart failure syndrome, with typical symptoms of dyspnoea, orthopnoea, and paroxysmal nocturnal dyspnoea, may result in these cases. Examination of these patients may reveal pulmonary congestion. Left atrial myxomas are typically mobile and pedunculated and may prolapse into the mitral valve orifice. This may result in obstruction of blood flow to the left ventricle as well as mitral regurgitation. The signs and symptoms may imitate mitral valve disease, namely dyspnoea, orthopnoea, and paroxysmal nocturnal dyspnoea. The occurrence of constitutional symptoms with mitral valve disease is less likely, and its presence should raise suspicions of a cardiac tumor. Another distinguishing feature is the uncommon occurrence of atrial fibrillation, presumably because of the absence of left atrial enlargement in patients with cardiac tumors. Additionally, the symptoms are paroxysmal and typically arise in a particular body position.
Thromboembolism Embolization of tumor fragments or thrombus from the surface of a tumor occurs frequently. Some myxomas are friable, and because they are intracavitary, they are the most frequent source of tumor emboli. Other types of tumors may occasionally embolize. Right-sided tumors may embolize to the lungs or systemically in the presence of intracardiac right-to-left shunts. Left-sided tumors embolize systemically resulting in stroke, visceral infarction, peripheral limb ischemia, and peripheral vascular aneurysms. An embolic stroke in a young person in sinus rhythm should raise the possibility of an intracardiac tumor. Multiple systemic emboli may mimic infective endocarditis or vasculitis.
Murmurs and heart sounds Systolic or diastolic murmurs may occur, particularly with murmurs in an intracavitary location. Murmurs causing obstruction of flow into the right or the left atrium may
Table 2
Clinical presentation of cardiac tumors*
Symptoms
Number
Congestive heart failure Thrombo-embolism Incidental/asymptomatic Chest discomfort Murmur Constitutional symptoms Dizziness Arrhythmia
8 (28%) 5 (17%) 6 (21%) 4 (14%) 3 (10%) 1 (3%) 1 (3%) 1 (3%)
*Adapted from Odim et al.6
Lewis
Cardiac Tumors
cause diastolic murmurs mimicking tricuspid or mitral stenosis, respectively. The S1 may be split, and there may be a tumor plop. This tumor plop occurs early in diastole and when due to a left-sided tumor is later than the opening snap of mitral stenosis and earlier than the S3. These tumors may also interfere with the valve apparatus, causing tricuspid or mitral regurgtiation.
Constitutional symptoms The presence of constitutional symptoms in a patient who may appear to have valvular abnormalities should raise the suspicion of a cardiac tumor. Weight loss, fever, arthralgias, and an elevated ESR may all occur.
Arrhythmias Intramural tumors may cause disturbances of conduction or rhythm depending on the location of the tumor. Tumors with atrial involvement or attachment, such as myxomas, sarcomas, and lipomas, may produce a wide variety of supraventricular tachyarrhythmias. This includes atrial fibrillation, atrial flutter, and ectopic atrial tachycardia. Tumors in the area of the atrioventricular node, typically angiomas and mesotheliomas, may produce conduction abnormalities such as complete heart block or asystole. Tumors within the ventricular myocardium may produce premature ventricular beats, ventricular tachycardia, ventricular fibrillation, and sudden cardiac death.
Investigation of cardiac tumors Imaging is an important tool in making a diagnosis of a cardiac tumor. As evident from the previous discussion, the clinical presentation may be quite nonspecific. The imaging modality of choice is the transthoracic echocardiogram (TTE), and where TTE is suboptimal, transesophageal echocardiography (TEE) is warranted. Cardiac CT or MRI is of no incremental value where the echocardiogram is of good quality and identifies the tumor, its exact location, and its attachments. To a lesser degree, a chest x-ray may yield some diagnostic information. Cardiac catheterization was the first method used to diagnose cardiac tumors antemortem, but is no longer used since the advent of echocardiography, cardiac CT, and MRI. Today the use of angiography is limited to special circumstances. Where good images are obtained, TTE can help make a diagnosis of cardiac myxoma with a fair degree of certainty. Typically, myxomas are located in the fossa ovalis of the interatrial septum. They are often pedunculated, with a very short stalk, which in the case of small tumors, may be nonexistent. TTE has limited use in the diagnosis of lipomas. Lipomas in the pericardial space are usually hypoechoic and have the appearance of fluid, whereas intracavitary lipomas tend to be hyperechoic. CT and MR offer
67 better diagnostic specificity in identifying fat and can thus yield an unequivocal diagnosis of lipoma. Studies have shown that the best imaging modality for a lipoma is the MRI.8 MRI is useful in verification of masses seen on TTE as well as for excluding masses when the TTE is equivocal. T1- and T2-weighted images provide detailed morphologic information. T1 gives excellent soft tissue characterization, and T2 provides superior soft tissue contrast and demonstration of fluid components. MRI allows for tissue characterization by comparing T1 and T2 values of masses to a reference tissue (fat). It is limited to the diagnosis of myxomas, fibromas, thrombi, and fatty tissue.8 Malignant primary cardiac tumors usually appear as broad-based right atrial mass(es) near the inferior vena cava (IVC), in contrast to myxomas, which almost invariably arise from the region of the fossa ovalis. Both CT and MRI are helpful in determining the degree of infiltration. As metastatic cardiac tumors affect the pericardium primarily, pericardial effusion is the most common echocardiographic finding. Renal cell carcinoma may spread along the IVC and extend into the right atrium. Both TTE and TEE are of limited value in evaluating masses in the mediastinum and pericardiac structures. CT scanning provides a high degree of soft tissue discrimination and is helpful in determining the degree of myocardial infiltration. Electron beam CT (EBCT) provides fast data acquisition rendering cardiac gating not absolutely necessary.9 Mosseaux and coworkers showed that EBCT provided additional anatomical information over TTE in patients with malignant tumors but not in those with myxomas.9 EBCT can show the extent of disease, including invasion of contiguous vessels and pulmonary metastases, better than TTE. It can also visualize neoplastic pulmonary emnboli. It also shows calcium, compared with MRI which does not show calcium, so is useful in patients with rhabdomyomas, fibromas, teratomas, myxomas, hemangiomas, and osteosarcoma. One of the major limitations of all the major current imaging modalities is their ability to accurately distinguish thrombus from benign and malignant tumors. The technique of contrast perfusion echocardiography has tried to improve the diagnostic accuracy of echocardiograms in this area. Kirkpatrick and coworkers demonstrated that malignant tumors that are more vascular than thrombus or benign tumors hyperenhance with contrast. This has been shown to be a reliable distinguishing feature.10
Conclusion Cardiac tumors are an important diagnostic entity. Recent data have demonstrated that the incidence of primary cardiac tumors has been underestimated in the past. Their protean manifestations do make the diagnosis challenging. A combination of clinical findings and appropriate imaging
68 techniques will help to clarify the diagnosis in most cases. The diagnosis is crucial as treatment in most cases is surgical. Some cases, though, will not be diagnosed with complete certainty preoperatively, owing to the limitations of the currently available imaging techniques.
References 1. Roberts WC: Primary and secondary neoplasms of the heart. Am J Cardiol 80:671-682, 1997 2. Reynan K: Frequency of primary tumors of the heart. Am J Cardiol 77:107-116, 1996 3. Yu K, Liu Y, Wang H, et al: Epidemiological and pathological characteristics of cardiac tumors: a clinical study of 242 cases. Interact Cardiovasc Thorac Surg 6:636-639, 2007
Seminars in Diagnostic Pathology, Vol 25, No 1, February 2008 4. Sarjeant JM, Butany J, Cusimano RJ: Cancer of the heart. Epidemiology and management of primary tumors and metastases. Am J Cardiovasc Drugs 3:407-421, 2003 5. Butany J, Nair V, Naseemuddin A, et al: Cardiac tumours: diagnosis and management. Lancet Oncol 6:219-228, 2005 6. Odim J, Reehal V, Laks H, et al: Surgical pathology of cardiac tumors. Two decades at an urban institution. Cardiovasc Pathol 12:267-276, 2003 7. Braunwald E: Heart Disease: A Textbook of Cardiovascular Medicine (ed 7). Philadelphia, PA, WB Saunders, 2005, pp 1731-1755 8. Hoffmann U, Globits S, Frank H: Cardiac and paracardiac masses. Current opinion on diagnostic evaluation by magnetic resonance imaging. Eur Heart J 19:553-563, 1998 9. Mousseaux E, Hernigou A, Azencot M, et al: Evaluation by electron beam computed tomography of intracardiac masses suspected by transesophageal echocardiography. Heart 76:256-263, 1996 10. Kirkpatrick JN, Wong T, Bednarz JE, et al: Differential diagnosis of cardiac masses using contrast echocardiographic perfusion imaging. J Am Coll Cardiol 43:1412-1419, 2004