AUTHOR INFORMATION	Section 1 of 12
Author Information Introduction Differentials Radiograph CT Scan MRI Ultrasound Nuclear Medicine Angiography Intervention Pictures Bibliography

Author: Julia Gates, MD, Consulting Staff and Assistant Residency Program Director, Department of Radiology, Baystate Medical Center Coauthor(s): George G Hartnell, MD, Professor of Radiology, Tufts University School of Medicine, Director of Cardiovascular and Interventional Radiology, Department of Radiology, Baystate Medical Center

Julia Gates, MD, is a member of the following medical societies: Alpha Omega Alpha, American Heart Association, American Roentgen Ray Society, Association of University Radiologists, Massachusetts Medical Society, Radiological Society of North America, and Society of Cardiovascular and Interventional Radiology

Editor(s): Justin D Pearlman, MD, ME, PhD, MA, Director of Dartmouth Advanced Imaging Center, Professor of Medicine, Professor of Radiology, Adjunct Professor, Thayer Bioengineering and Computer Science, Dartmouth-Hitchcock Medical Center; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; John D Newell, Jr, MD, FACR, FCCP, FASER, Co-Director of Thoracic Imaging, UCDHSC; Director of Lung Imaging Center, Professor of Radiology and Professor of Medicine, Department of Radiology, University of Colorado Health Sciences Center, National Jewish Medical and Research Center; Univ. Colorado Hospital; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; and Eugene C Lin, MD, Consulting Staff, Department of Radiology, Virginia Mason Medical Center

Disclosure

	INTRODUCTION	Section 2 of 12
Author Information Introduction Differentials Radiograph CT Scan MRI Ultrasound Nuclear Medicine Angiography Intervention Pictures Bibliography

Background: Cardiac neoplasms may be primary or secondary, they may be related to the heart muscle or the pericardium, or they may occur by means of direct extension of primary tumors or by means of metastases from adjacent structures.

The presence of a cardiac tumor upon clinical examination and electrocardiography was first documented in 1934. Until that time, cardiac tumors were identified postmortem (Majano-Lainez, 1997). Angiography first was used to demonstrate a cardiac tumor within a chamber in 1951 (Majano-Lainez, 1997).

In general, primary cardiac tumors are of mesothelial or epithelial origin. Tumors include myxoma (see Images 1-13), fibroma, lipoma (see Image 14), rhabdomyoma, plasma cell granuloma, sarcoma, lymphoma (see Image 15), thymoma, hemangiopericytoma (see Images 16-19), fibroelastoma (see Images 20-21), angioma, hemangioma, angiomyolipoma/hamartoma, lymphangioma, and mycosis fungoides (Waller, 1989; Inoue, 2000; Gosalbez, 1999; Nakamura, 1987; Shapiro, 2001; Kemp, 1996; Grenadier, 1989; Tsai, 1997; Pasaoglu, 1991; Roberts, 1968).

Endodermal tumors also can be found. For example, atrioventricular (AV) nodal tumors may contain neuroendocrine cells, and thus they may be of endodermal origin, representing the so-called polycystic tumor of the AV node or congenital endodermal heterotopia of the AV node (Fine, 1987; Linder, 1984). Cardiac paragangliomas also have been described. Patients with these tumors present with hypertension and elevated urinary catecholamine levels (Johnson, 1985; Conti, 1986; Cane, 1996). The tumors tend to be left sided. Intracardiac pheochromocytomas also occur (Fitzgerald, 1995; Chang, 1991).

Myxomas usually are found in the left heart, but they do occur, less often, on the right (Symbas, 1976). Myxomas tend to be solitary and occur more often in women than in men. They are characteristically attached to the interatrial septum adjacent to the edge of the fossa ovalis in approximately 85% of patients (Schvartzman, 2000). Myxomas can invade the interatrial septum and the opposite atrium (Peachell, 1998). Tumors may be pedunculated (see Images 10-13) or polypoid (see Images 3-5) (Schvartzman, 2000).

Firm, oval masses are associated with dyspnea and show small vessels, tortuous vascularity, hemorrhage, and fibrosis. Soft papillary tumors tend be associated with neurologic symptoms and brain infarcts (Shimono, 1995). Almost one half may have surface thrombus, and almost one half may have fibrosis (Burke, 1993). Patients with left-heart myxomas may present with mitral valve obstruction (see Images 1-2 and Images 10-13) or features suggesting subacute bacterial endocarditis. Patients with right-heart myxomas may present with tricuspid valve disease, pulmonary embolism, or pulmonary hypertension (Symbas, 1976; Seemann, 1996).

Primary cardiac sarcomas encompass a broad spectrum of tumors that includes angiosarcoma (see Image 22), osteosarcoma, fibrosarcoma, malignant fibrous histiocytoma, leiomyosarcoma (see Images 23-24), myxosarcoma, synovial sarcoma, neurofibrosarcoma, lymphosarcoma, reticulum cell sarcoma, and undifferentiated sarcoma (Ohtahara, 1996; Dan, 1997; Lim, 1998; Seal, 1997; Fang, 1996; Lo, 1998; Davis, 1997; Kojima, 1999; Roberts, 1968; Burke, 1992; Araoz, 1999). Angiosarcomas tend to be located in the right heart (see Image 22), and osteosarcomas tend to be found in the left heart (Burke, 1992; Araoz, 1999). Primary cardiac liposarcoma has been reported; it is extremely rare and part of the differential diagnosis of a mass with fat signal intensity on MRIs. Most liposarcomas involving the heart either arise from the pericardial or are metastatic. All are rare.

Patients have been aged 1-75 years at presentation and may present with symptoms secondary to distal metastases (Burke, 1992; Shapiro, 1999; Romero-Menor, 1995; Colon, 1995). Osteosarcomas tend to calcify and are usually found in the left atrium (Araoz, 1999). Angiosarcomas are the most common primary cardiac malignant tumor, and leiomyosarcomas are the second most common malignant primary tumors of the heart. Leiomyosarcoma frequently invades the mitral valve and pulmonary veins, and it frequently involves the left atrium (Araoz, 1999). Other common sarcomas include rhabdomyosarcomas and fibrosarcomas. Fibrosarcoma is frequently necrotic and favors the left atrium (Araoz, 1999).

Metastatic disease may result from contiguous extension, lymphangitic spread, or hematogenous spread (Kapoor, 1986). Metastatic cardiac tumors are frequently bronchogenic carcinomas (see Images 25-26), breast carcinomas, lymphomas, leukemias, carcinoid tumors, or melanomas (McAdams, 1989; Roberts, 1968; Burn, 1999). Metastatic cervical carcinoma has been reported (Cutrone, 1995). Metastases to the heart tend to involve the myocardium rather than the valves and endocardium (Schvartzman, 2000). Alternatively, contiguous extension of tumor may come from primary or metastatic disease. For example, metastases to the lung can invade the mediastinum by means of local extension, such as by a malignant thymoma (Zissin, 1999; Korobkin, 1989). Liver cancer, such as hepatocellular carcinoma, can extend cephalad via the inferior vena cava into the heart (Wigmore, 1999).

Other abdominal tumors can affect the heart; extension of tumor thrombus via the inferior vena cava into the right atrium is a well-recognized complication of advanced renal cell carcinoma (see Image 27), and it also can occur with cervical carcinoma and renal angiomyolipomas (Ogawa, 1999; Vargas-Barron, 1990; Rothenberg, 1986). Benign uterine leiomyomatosis also can affect the heart intravenously (Steinmetz, 1996; Okamoto, 1994; Kaszar-Seibert, 1988). Germ cell tumors (eg, testicular teratomas) and embryonal cell carcinomas can metastasize to the heart, as can choriocarcinomas (Pickuth, 1992; Paule, 1991; Chandrashekar, 1995). Thyroid metastases have been seen (Haggerty, 1990). Musculoskeletal tumors, such as hemangiopericytomas, also can metastasize and grow in the heart (Sato, 1995).

Primary pericardial tumors include malignant spindle tumor, localized fibrous tumor (also called localized fibrous mesothelioma), pericardial cysts (see Images 28-30), liposarcoma, lipoma (see Image 31), and teratoma (Fukuda, 1989; el-Naggar, 1989; Watanabe, 1999; Andreani, 1998; Araoz, 1999; Romer, 1999; Doshi, 1998; Bitar, 1998). Cardiac angiosarcomas tend also to involve the pericardium secondarily and to produce hemorrhagic pericardial effusions (Kim, 1989).

Pericardial mesotheliomas frequently are associated with asbestos exposure. Most specimens have identifiable asbestos fibers, particularly crocidolite and amosite fibers, as well as chrysotile to a lesser extent (Morinaga, 1989). However, not all mesotheliomas arise in patients with a prior history of asbestos exposure (Watanabe, 1999). Lymphomas frequently are found in patients who are immunocompromised and frequently involve the pericardium (Araoz, 1999). Liposarcomas are rare tumors, they tend to be extracardiac, and they tend to form large infiltrating masses (Araoz, 1999).

Primary tumors of the cardiac valves and chordae are uncommon; however, when they do occur, most often, they are fibroelastomas (Graca, 1999; Di Mattia, 1999; Cesena, 1999; de Menezes, 1996). Fibroelastomas are small tumors that may be an incidental finding at autopsy (see Images 20-21). They can be mistaken for a valve vegetation. Lipomatous tumors of the heart valves also have been described (Benvenuti, 1996).

Primary cardiac tumors appearing in childhood include rhabdomyomas, intrapericardial teratomas, myxomas, fibromas, hemangiomas, mesotheliomas, multicystic hamartomas, epicardial lipomas, and rhabdomyosarcomas; some tumors cannot be identified pathologically (de Bustamante, 2000; Sievers, 2000; Sallee, 1999; Beghetti, 1997). Rhabdomyomas are the most common pediatric cardiac tumor, and most children with rhabdomyomas have tuberous sclerosis (Sallee, 1999). Rhabdomyomas can affect all 4 cardiac chambers (Takatoh, 1988). Rhabdomyomas frequently resolve spontaneously (Shapiro, 2001). Most primary pediatric tumors are diagnosed in the first year of life (Sallee, 1999). Rhabdomyosarcoma is the most common pediatric malignant cardiac primary neoplasm. Compared with other primary cardiac sarcomas, rhabdomyosarcomas are more likely to involve the valves (Araoz, 1999).

Primary pediatric cardiac tumors present with murmurs and arrhythmias (Sallee, 1999). Intrapericardial tumors can cause airway compression and subsequent dyspnea. In utero, fetuses can present with abnormal sonogram findings (Czechowski, 2000). The tumors can cause conduction abnormalities. Conduction abnormalities can be evaluated by electrophysiology testing and may be amenable to radiofrequency ablation (Sallee, 1999).

Some cardiac masses may not be tumors. Non-neoplasms or pseudotumors include thrombus or variants of cardiac anatomy, eg, prominent pulmonary vein orifice (see Images 32-33), right atrial Chiari network or crista terminalis (see Images 34-35), valvular vegetation, thrombus within a left ventricular aneurysm, lipomatous hypertrophy of the interatrial septum (see Image 36), rheumatoid nodule, pulmonary collapse, ruptured chordae tendineae, intracardiac varices, tumors outside the heart and pericardium (can resemble a cardiac mass, eg, phrenic nerve tumor), and anatomic structures, such as hiatal hernia (see Image 37; Kindman, 1998; Webber, 1995; Plehn, 1988; Atalay, 1995; Harrity, 1995; Ewy, 1995).

Frequency:

• In the US: The frequency of cardiac tumors is dependent on the frequency of autopsy and the patient population being evaluated (see also Age).
  • Benign primary tumors are more frequent than primary malignant tumors. In autopsy series, the cumulative prevalence of primary cardiac tumors is 0.001-0.3% (Urba, 1986; McAllister, 1979).

    Overall, myxomas account for approximately 30% of all primary cardiac neoplasms. Of atrial myxomas, 90% occur on the left and 90% are solitary (Shapiro, 2001). Angiosarcomas account for 33% of all malignant primary cardiac neoplasms, and myxomas account for approximately 50% of all benign primary cardiac neoplasms (Shapiro, 2001). Lipomas are the second most common benign cardiac tumor and account for approximately 10% of all cardiac neoplasms (Hoffmann, 1998; Vanderheyden, 1998). The most common intracardiac mass is thrombus (Schvartzman, 2000).

  • Secondary tumors are accepted to be more common than primary tumors by a factor of 20-30.

  • Metastatic tumors to the heart and pericardium are more common than primary neoplasms and occur in as many as 1.5% of patients with malignancies (Schvartzman, 2000). The most common sources of metastatic tumors are as follows (in approximate order of frequency): bronchogenic carcinoma of the breast; lymphoma; leukemia; esophagus; uterus; melanoma; stomach; sarcomas; germ cell tumors; and tumors of the oral/tongue, colon/rectum, kidney, thyroid, larynx, urinary bladder, hepatobiliary system, prostate, pancreas, and ovary (Roberts, 1998).

• Internationally: The incidence is identical to that in the United States.

Mortality/Morbidity:

• Angiosarcomas have a high mortality rate, and most patients do not survive beyond 6 months of the diagnosis (Shapiro, 2001).

• Mortality rates in patients with other malignant tumors also are high, especially in those with metastases, which tend to involve the heart late in the course of malignant disease.

• Benign tumors can usually be resected and have a good prognosis.

Race: No data about racial factors are available.

Sex:

• Cardiac myxomas tend to occur more often in women than in men (Shapiro, 2001).

• Cardiac lipomas have no sex predilection (Schvartzman, 2000).

• Rhabdomyosarcomas and angiosarcomas are more common in males than in females (Shapiro, 2001).

Age: Patients with primary cardiac sarcomas have presented at age 1-75 years (Burke, 1992). Cardiac lipomas occur in patients of any age (Schvartzman, 2000).

• Pediatric tumors: Most primary pediatric tumors are diagnosed within the first year of life (Sallee, 1999).
  
  Among pediatric patients, primary cardiac neoplasms include rhabdomyoma (78%), fibroma (11%), pericardial teratoma (2%), epicardial lipoma (2%), multicystic hamartoma (2%), and unspecified (5%; Beghetti, 1997).
  
  In children aged 15 years or younger, the most common benign primary cardiac tumors are as follows: rhabdomyoma (the most common benign primary tumor in those <1 y of age and associated with tuberose sclerosis in 30-50%), fibroma, hemangioma, and teratoma (Roberts, 1998).
  
  In children aged 15 years or younger, the most common malignant primary cardiac tumors are as follows: rhabdomyosarcoma fibrous histiocytoma, angiosarcoma, fibrosarcoma, and myxoid sarcoma (Roberts, 1998).

Lipomatous hypertrophy of the interatrial septum frequently is found in people with obesity (Shapiro, 2001) (see Image 36).

Most children with rhabdomyomas also have tuberous sclerosis, which is associated with adenoma sebaceum, seizures, and mental retardation.

Preferred Examination: Initially, intracardiac tumors are often best evaluated by using echocardiography. Differentiation of left atrial masses from thrombus may best be achieved by using transesophageal echocardiography. Owing to a larger field of view with a better opportunity to assess contiguous extracardiac involvement or the presence of metastatic disease, MRI, magnetic resonance angiography (MRA), and CT are preferred over echocardiography for less-straightforward cases or for cases in which acoustic access is restricted.

Limitations of Techniques: Chest radiography may show the effects of intracardiac obstruction with features of pulmonary edema (see Images 1-2), but otherwise, they may contribute little. Echocardiography is easily accessible, but it is limited by restricted acoustic access. CT scanning is accurate, but it requires radiation and contrast material. In suitable patients, MRI has the fewest limitations provided that the patient can remain motionless during the examination.

	DIFFERENTIALS	Section 3 of 12
Author Information Introduction Differentials Radiograph CT Scan MRI Ultrasound Nuclear Medicine Angiography Intervention Pictures Bibliography

Chondrosarcoma
Leiomyoma, Uterus (Fibroid)
Liposarcoma, Soft Tissue
Mesothelioma, Malignant
Osteosarcoma, Variants
Pheochromocytoma
Renal Cell Carcinoma

Other Problems to be Considered:

Primary cardiac tumors - Myxoma, fibroma, lipoma, rhabdomyoma, plasma cell granuloma, sarcoma, lymphoma, thymoma, hemangiopericytoma, fibroelastoma, mycosis fungoides, hamartoma/angiomyolipoma, hemangioma, angioma, lymphangioma, and pheochromocytoma

Primary cardiac sarcomas - Angiosarcoma, osteosarcoma, fibrosarcoma, malignant fibrous histiocytoma, leiomyosarcoma, myxosarcoma, synovial sarcoma, neurofibrosarcoma, liposarcoma, lymphosarcoma, reticulum cell sarcoma, and undifferentiated sarcoma

Metastatic tumors - Bronchogenic carcinoma, breast carcinoma, lymphoma, leukemia, carcinoid tumor, melanoma, cervical carcinoma, and germ cell tumors

Primary pediatric cardiac tumors - Rhabdomyoma, intrapericardial teratoma, myxoma, fibroma, hemangioma, mesothelioma, multicystic hamartoma, epicardial lipoma, and rhabdomyosarcoma

Pericardial tumors - Malignant spindle tumor, localized fibrous tumor (also termed localized fibrous mesothelioma), pericardial cyst, direct extension of primary cardiac tumors, or lung cancer

	RADIOGRAPH	Section 4 of 12
Author Information Introduction Differentials Radiograph CT Scan MRI Ultrasound Nuclear Medicine Angiography Intervention Pictures Bibliography

Findings: Plain radiography is not an effective method for screening for cardiac neoplasms or evaluating the extent of tumor.

• Cardiac myxomas may be calcified, and hence, they may be visible on lateral chest radiographs.

• Left atrial enlargement may be noted; this may result from mitral valve obstruction (see Images 1-2).

• Disease that expands the cardiac silhouette, by either bulk or secondary effusion, may be suggestive of pericardial involvement.

Degree of Confidence: The degree of confidence is limited. Plain radiographic changes in cardiac tumors are nonspecific.