Tumors, Masses, and Source of Emboli
Shepard D. Weiner
Shunichi Homma
1. A structure found in the left atrium that can be misinterpreted as a pathologic mass is:
A. Eustachian valve.
B. Crista terminalis.
C. Moderator band.
D. Chiari network.
E. Suture line following transplant.
View Answer
1. Answer: E. There are many normal variants and benign conditions that can be misinterpreted on two-dimensional echocardiography as pathologic entities. A suture line following transplant is an example of a structure found in the left atrium that can be misinterpreted as a mass. The eustachian valve, crista terminalis, and Chiari network are all normal structures found in the right atrium. The moderator band is a normal structure present in the right ventricle.
2. The following is a class IIb indication for performing echocardiography in patients with cardiac masses or tumors:
A. Evaluation of patients with clinical syndromes and events suggesting an underlying cardiac mass.
B. Follow-up or surveillance studies after surgical removal of masses known to have a high likelihood of recurrence.
C. Screening persons with disease states likely to result in mass formation but for whom no clinical evidence for the mass exists.
D. Evaluation of patients with underlying cardiac disease known to predispose to mass formation for whom a therapeutic decision regarding surgery or anticoagulation will depend on the results of echocardiography.
E. Patients with known primary malignancies when echocardiographic surveillance for cardiac involvement is part of the disease staging process.
View Answer
2. Answer: C. Screening persons with disease states likely to result in mass formation but for whom no clinical evidence for the mass exists is a class IIb indication for performing echocardiography. Class I indications for echocardiography include evaluating patients with clinical syndromes suggesting an underlying cardiac mass, follow-up studies after surgical removal of masses known to recur, evaluating patients where treatment plans depend on the results of echocardiography, and assessing patients with known primary malignancies where surveillance for cardiac involvement is part of the disease staging process.
3. This tumor is a benign cardiac tumor:
A. Angiosarcoma.
B. Rhabdomyoma.
C. Lymphoma.
D. Mesothelioma.
E. Prominent ventricular trabeculations.
View Answer
3. Answer: B. Rhabdomyoma is a benign cardiac tumor. Rhabdomyomas are usually small and lobulated, with diameters in the range of 2 mm to 2 cm. Rhabdomyomas are most often multiple and are strongly associated with tuberous sclerosis. Angiosarcoma, lymphoma, and mesothelioma are all malignant cardiac tumors. Prominent ventricular trabeculations can also be seen on echocardiography and represent either a normal variant, or, if severe enough may indicate noncompaction.
4. It is uncommon for this tumor to metastasize to the heart:
A. Renal cell carcinoma.
B. Breast.
C. Thyroid.
D. Lung.
E. Melanoma.
View Answer
4. Answer: C. It is uncommon for thyroid cancer to metastasize to the heart. Renal cell carcinoma, breast cancer, lung cancer, and melanoma all are known to metastasize to the heart. Table 29-1 lists the primary cancers that metastasize to the heart. Renal cell carcinoma spreads hematogenously to the inferior vena cava and right side of the heart. Breast cancer spreads to the heart by either hematogenous or lymphatic means. Lung cancer usually metastasizes to the heart via direct extension. Lymphoma spreads through the lymphatic system. Metastatic melanoma can result in intracavitary or myocardial involvement. Carcinoid typically results in tricuspid and pulmonic valve thickening.
Table 29-1. Tumors That Metastasize to the Heart | ||||||||||||||||
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5. Cardiac tumors are characterized by the following:
A. Primary cardiac tumors are a common cardiac condition.
B. Cardiac tumors are almost always symptomatic.
C. Echocardiography is a costly and inconvenient test to evaluate a cardiac tumor.
D. Embolization is a mechanism by which cardiac tumors cause symptoms.
View Answer
5. Answer: D. Cardiac tumors may cause symptoms through a variety of mechanisms. Embolization is one mechanism, which is usually in the systemic circulation but can also occur in the pulmonic circulation. Aortic valve and left atrial tumors are associated with the greatest risk of embolization. Other mechanisms of symptom production include obstruction, interference with valves causing regurgitation, direct invasion of the myocardium (leading to impaired contractility, arrhythmias, heart block, or pericardial effusion), and constitutional or systemic symptoms. Primary cardiac tumors are rare. Incidence has been estimated to be at <1% (closer to 0.1%) based on autopsy studies. Cardiac tumors may be symptomatic or found incidentally during evaluation for an unrelated problem or physical findings. Echocardiography is the simplest technique for evaluating a cardiac tumor, although at times a cardiac MRI or CT scan may be needed to provide more detailed information.
6. Lipomatous hypertrophy of the atrial septum:
A. Does not commonly cause symptoms.
B. Is caused by fibrosis.
C. Has the same histologic pattern as lipomas.
D. Can be seen on transthoracic echocardiography and is an indication for the performance of transesophageal echocardiography.
View Answer
6. Answer: A. Lipomatous hypertrophy of the atrial septum does not commonly cause symptoms. This condition is thought to be benign, although there is a reported association with atrial arrhythmias and superior vena cava obstruction if there is massive lipomatous hypertrophy. The atrial septum is infiltrated by lipomatous material that results in thickening of the inferior and superior portions. The fossa ovalis is spared and results in a “dumbbell-shaped” appearance on two-dimensional echocardiography. Lipomatous hypertrophy of the atrial septum is usually distinguishable by the highly refractile echogenic quality of fat. Although no absolute diagnostic criteria have been established, a septal thickness of 20 mm is often quoted. Lipomatous hypertrophy of the atrial septum represents a hamartoma. Pathologically, in contrast to true lipomas, lipomatous hypertrophy consists of a nonencapsulated accumulation of mature and fetal adipose tissue and atypical cardiac myocytes within the interatrial septum. The term hypertrophy is a misnomer since the condition is due to an increased number rather than an increased size of adipocytes. This condition can be seen on transthoracic echocardiography and its presence alone is not an indication for transesophageal echocardiography.
7. The transesophageal echocardiographic evaluation of valvular vegetations:
A. Always allows for the distinction from other cardiac masses.
B. Can provide predictive information about embolic risk.
C. Has shown that vegetations are more likely to be on the “downstream” side of the valve.
D. Has not been used to determine the natural history of vegetations.
E. Is not influenced by pretest expectations.
View Answer
7. Answer: B. Although some data are conflicting, in general larger vegetation size on transesophageal echocardiography appears to be predictive of embolic risk. Patients with a vegetation diameter above 10 mm have been shown to have a significantly higher incidence of embolic events than those with smaller vegetations. This association has been shown to be strongest in patients with mitral valve endocarditis. The sensitivity and specificity of transesophageal echocardiography for detecting vegetations is 92% and 96%, respectively. False-positive findings on transesophageal echocardiograms may occur due to small irregularities and degenerative processes. For example, mobile strands are frequently encountered on valves that probably represent a normal degenerative process; these strands are known as Lambl’s excrescences. Valvular vegetations are usually on the “upstream” side of the valve and characteristically prolapse into the upstream chamber (i.e., mitral vegetations into the atrium in systole and aortic vegetations in the left ventricular outflow tract during diastole). Echocardiography has been used to determine the natural history of vegetations. An increase in size suggests active disease. Pretest expectations for endocarditis should lead to an expanded scrutiny of the valves with extra images. However, as sensitivity rises, specificity may be reduced, and this must also be taken into consideration.
8. Which of the following statements about a patent foramen ovale is correct?
A. Patent foramen ovale is a rare congenital cardiac lesion that is estimated to occur in 1% of the population.
B. The prevalence of patent foramen ovale is three times more frequent in females compared to males.
C. Most individuals with patent foramen ovale are symptomatic.
D. An incidentally detected patent foramen ovale requires surgical or percutaneous closure.
E. Early saline contrast appearance in the left heart (within three beats of contrast appearance in the right heart) on transthoracic echocardiography with agitated saline contrast injection is consistent with the presence of a patent foramen ovale.
View Answer
8. Answer: E. The timing of the appearance of agitated saline contrast (bubbles) in the left heart on echocardiography can help distinguish intracardiac shunting (via patent foramen ovale or atrial septal defect) from pulmonary arteriovenous shunting. Early contrast appearance in the left heart (within three beats of contrast appearance in the right heart) suggests intracardiac shunting, while late shunting (after three to five beats) is more consistent with pulmonary arteriovenous shunting. However, exceptions to this timing construct do occur. Patent foramen ovale is a congenital cardiac lesion that frequently persists into adulthood. Patent foramen ovale has been found to be present in 25%-30% of individuals in autopsy studies and community-based transesophageal echocardiography studies. The prevalence and size of patent foramen ovale is similar in females and males. Most individuals with patent foramen ovale are asymptomatic. An incidentally detected patent foramen ovale generally requires no follow-up or treatment. If a patent foramen ovale is deemed likely to be causally related to an embolic event, therapeutic options for secondary stroke or other embolic event prevention are controversial and include medical therapy with antiplatelet agents or anticoagulation, and surgical or percutaneous closure of the defect in certain settings. Evaluation of sources of venous thromboembolism is also suggested since identification of venous thrombosis provides further support for paradoxical embolism as the mechanism of the embolic event and has treatment implications.
9. The clinical manifestations of the Carney complex include:
A. Papillary fibroelastoma.
B. Hemangioma.
C. Epilepsy.
D. Cardiac myxoma.
E. Nevoid basal cell carcinoma.
View Answer
9. Answer: D. The diagnostic criteria for the Carney complex include having 2 of 12 recognized clinical manifestations or one clinical manifestation plus one of the two genetic criteria (Table 29-2). Cardiac myxoma is a diagnostic clinical criterion for the Carney complex. The other clinical manifestations relate to either pigmented skin lesions or endocrine neoplasia. Familial myxomas, such as those seen in the Carney complex, account for a small percentage of all myxomas. Patients with familial myxomas tend to present earlier, are more likely to have myxomas in atypical locations, may have multiple myxomas, and are more likely to develop recurrent tumors. Epilepsy is associated with tuberous sclerosis. Nevoid basal cell carcinoma is associated with cardiac fibroma in the Gorlin syndrome.
Table 29-2. Carney Complex Diagnostic Criteria | |||||
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10. The following are symptoms associated with cardiac myxoma:
A. Palpitations and diarrhea.
B. Syncope and diarrhea.
C. Dyspnea and fever.
D. Dyspnea and dysphagia.
View Answer
10. Answer: C. Myxomas present with symptoms resulting from intracardiac obstruction, systemic embolization, or constitutional symptoms. Dyspnea is the most common symptom. Syncope and palpitations are also seen. Constitutional symptoms, such as fever and weight loss, are also seen in approximately 15%-20% of patients. The association of constitutional symptoms with cardiac myxoma is likely due to the tumor’s synthesis and secretion of interleukin (IL)-6. IL-6 is a proinflammatory cytokine that induces the acute phase response. Increased levels of IL-6 have been found in myxoma tissue and the constitutional symptoms resolve after removal of the myxoma. Diarrhea is seen in the carcinoid syndrome.
11. Which of the following statements about tuberous sclerosis is true?
A. Tuberous sclerosis is a syndrome characterized by hamartomas in several organs, epilepsy, cognitive impairment, and adenoma sebaceum.
B. The genetic defect for tuberous sclerosis has not been identified.
C. Only a minority of patients with cardiac rhabdomyomas have tuberous sclerosis.
D. Surgical resection of the cardiac tumors is recommended in asymptomatic patients with tuberous sclerosis.
View Answer
11. Answer: A. Histologic evidence suggests that cardiac rhabdomyomas are actually myocardial hamartomas or malformations that are composed of myocytes rather than true neoplasms. The microscopic hallmark is a large (<80 µm diameter) cell containing a central cytoplasmic mass that is suspended by myofibrillar processes, termed the spider cell. Tuberous sclerosis is an autosomal-dominant hamartoma syndrome whose causative genes (TSC-1 and TSC-2) are tumor suppressor genes that encode a protein complex that regulates cell size. At least 80% of patients with cardiac rhabdomyomas have tuberous sclerosis. Fifty percent or more of cardiac rhabdomyomas regress spontaneously after infancy. Therefore, in the absence of symptoms, surgery is not indicated.
12. Papillary fibroelastomas:
A. Cannot occur on the pulmonic valve.
B. Are usually single rather than multiple.
C. Exclusively occur on cardiac valves.
D. Commonly result in valvular regurgitation.
View Answer
12. Answer: B. More than 90% of papillary fibroelastomas are single. Papillary fibroelastomas can occur on any valve. The aortic and mitral valves are most commonly involved in adults. Despite their valvular attachment, valve dysfunction is rare. Much less commonly, papillary fibroelastomas can occur on papillary muscle, chordae tendineae, or in the atria. The median diameter of papillary fibroelastomas is 8 mm and the largest reported is 40 mm. A short pedicle is seen approximately 50% of the time, and is more typical in tumors arising from the endocardium of a cardiac chamber.
13. The most common malignant tumor of the heart is:
A. Angiosarcoma.
B. Lymphoma.
C. Metastatic disease.
D. Leiomyosarcoma.
E. Myxoma.
View Answer
13. Answer: C. Primary malignant tumors of the heart are much less common than metastatic tumors to the heart. In autopsy series, the incidence of primary tumors of the heart was only 0.02%. The relative incidence of primary tumors of the heart (both benign and malignant) is shown in Table 29-3.
Table 29-3. Relative Incidence of Primary Cardiac Tumors | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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14. A characteristic feature of a cardiac myxoma on two-dimensional echocardiography is:
A. An associated pericardial effusion.
B. A narrow stalk connected to the fossa ovalis.
C. An intramural hyperechoic mass.
D. A mobile mass with a short pedicle attached to a cardiac valve.
View Answer
14. Answer: B. Cardiac myxomas typically have a narrow stalk connected to the fossa ovalis. Approximately 75% of cardiac myxomas occur in the left atrium, where the site of attachment is almost always in the region of the fossa ovalis of the interatrial septum. Cardiac myxomas may occasionally be found on the posterior wall of the left atrium. However, this location within the left atrium should raise the suspicion for a malignant cardiac tumor. Approximately 15%-20% of cardiac myxomas occur in the right atrium, and less often they can be seen in the right or left ventricle. There are case reports of myxomas originating from the atrioventricular valves. Pericardial effusions are usually found in the setting of malignant cardiac tumors. Lipomas appear as an intramural hyperechoic mass. A mobile mass with a short pedicle attached to a cardiac valve is a papillary fibroelastoma.
15. In patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS), this tumor has been described to affect the heart:
A. Lipoma.
B. Kaposi sarcoma.
C. Rhabdomyosarcoma.
D. Angiosarcoma.
E. Hemangioma.
View Answer
15. Answer: B. Kaposi sarcoma, as well as malignant lymphoma, is recognized to occur in the setting of AIDS. Cardiac involvement with Kaposi sarcoma usually occurs as part of a disseminated Kaposi sarcoma. The incidence of Kaposi sarcoma involving the heart has been estimated to be 12%-28% by autopsy studies.
16. A 36-year-old woman was diagnosed with leiomyosarcoma (Fig. 29-1 of a zoomed view of the left atrium on parasternal long-axis). Which of the following statements about leiomyosarcoma is correct?
A. Treatment of cardiac leiomyosarcomas consists solely of chemotherapy and radiation.
B. Leiomyosarcomas, like other malignant cardiac tumors, occur preferentially in the right heart.
C. Leiomyosarcomas typically present in patients’ seventh decade.
D. Leiomyosarcomas are derived from smooth muscle cells.
 Figure 29-1 |
View Answer
16. Answer: D. Leiomyosarcomas are derived from smooth muscle cells and may originate from the smooth muscle cells lining the pulmonary veins. Although chemotherapy and radiation are part of the treatment plan, they are adjuncts to radical surgical resection. However, cardiac leiomyosarcomas have a poor prognosis, with a mean survival after surgery of less than 7 months. The majority of malignant tumors occur preferentially in the right side of the heart, with the exception of leiomyosarcoma, which often occurs in the left atrium. The preferential left atrial location and the frequently myxoid appearance of leiomyosarcomas makes them difficult to differentiate preoperatively from atrial myxomas. Unlike myxomas, leiomyosarcomas may originate from the posterior wall of the left atrium and involve the pulmonary veins. Patients with leiomyosarcoma typically present in their 30s, a decade younger than with other types of sarcomas.
17. A 40-year-old man with dyspnea is found to have a mass on transthoracic echocardiography (Fig. 29-2 of the right ventricular outflow tract in the pulmonic valve tilt view from parasternal longaxis, and Video 29-1). Pathology at the time of surgery revealed an angiosarcoma. Which of the following accurately describes angiosarcomas?A. Angiosarcomas usually are discovered late and typically have grown to be large or metastasized at the time of diagnosis.
B. Like other cardiac sarcomas, the gender distribution is equal (1:1).
C. Angiosarcomas most often occur in the left ventricle.
D. Patients usually present with tachyarrhythmias.
 Figure 29-2 |
View Answer
17. Answer: A. Angiosarcomas usually are large or have metastasized at the time of diagnosis. Angiosarcomas often are not amenable to complete resection and have a very poor prognosis, even compared to the other cardiac sarcomas. Unlike other sarcomas, which have a 1:1, gender ratio, there appears to be a 3:1 male-to-female ratio among patients with angiosarcoma. Angiosarcomas have a strong predilection for the right heart, particularly the right atrium. They can be either intracavitary or diffuse and infiltrative. The common presentation is rightsided heart failure or cardiac tamponade as well as constitutional symptoms.
18. A 52-year-old woman presented with right flank pain and weight loss. Renal cell carcinoma was diagnosed. A transthoracic echocardiogram was performed (Fig. 29-3 of the parasternal long-axis). Arrow points to a mass in the right ventricle. Which of the following statements about renal cell carcinoma is correct?
A. Intravascular extension of the tumor is not a common manifestation of renal cell carcinoma.
B. Pulmonary embolization is not seen with metastatic renal cell carcinoma.
C. Metastatic renal cell carcinoma is rarely confused with thrombus on echocardiography.
D. The initial diagnosis of renal cell carcinoma can be made by detection of an intracardiac mass on echocardiography in some cases.
 Figure 29-3 |
View Answer
18. Answer: D. Some patients with renal cell carcinoma may present with symptoms related to cardiac metastases. The diagnosis of renal cell carcinoma may be first introduced by the echocardiogram. Intravascular extension of tumor is a common manifestation of renal cell carcinoma. Since vena caval and right heart involvement is known to occur with metastatic renal cell carcinoma, pulmonary embolism, either from tumor or thrombus, can be seen. The appearance of metastatic renal cell carcinoma itself can be confused with thrombus on echocardiography and sometimes cardiac magnetic resonance imaging is helpful to distinguish these entities.
19. A 24-year-old man with synovial sarcoma had a transthoracic echocardiogram performed (Fig. 29-4 of the apical 4-chamber view demonstrating a large pericardial effusion and mass abutting the lateral left atrial wall, and Video 29-2). Which of the following accurately characterizes synovial sarcomas?A. Synovial sarcoma is caused by a translocation between chromosome 18 and the X chromosome.
B. Synovial sarcoma is not a malignant primary cardiac tumor.
C. Synovial sarcoma is a common type of cardiac tumor.
D. Synovial sarcoma has an excellent prognosis.
 Figure 29-4 |
View Answer
19. Answer: A. Synovial sarcoma is caused by a translocation between chromosome 18 and the X chromosome. Synovial sarcoma is one of the malignant primary cardiac sarcomas. Synovial sarcoma is an extremely rare cardiac tumor. Like most cardiac sarcomas, the prognosis of synovial sarcoma is poor.
20. A 0.2 mL bolus of perflutren lipid microspheres was injected intravenously followed by a saline flush. A 2-chamber view at 80 degrees on a transesophageal echocardiogram is shown in Figure 29-5 and Video 29-3. Based on these images, which of the following conclusions is true about this patient’s condition?A. The structure seen in the left atrium near the mitral annulus is likely to be an angiosarcoma.
B. The structure seen in the left atrium near the mitral annulus is likely to be a cystic structure.
C. The structure seen in the left atrium near the mitral annulus is likely to be a myxoma.
D. The structure seen in the left atrium near the mitral annulus is likely to be a papillary fibroelastoma.
 Figure 29-5
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