(Radiographics. 2002;22:673-689.)
© RSNA, 2002
From the Archives of the AFIP
Cardiac Myxoma: Imaging Features in 83 Patients1
Mary L. Grebenc, CDR, MC, USNR,
Melissa L. Rosado-de-Christenson, Col, USAF, MC,
Curtis E. Green, MD,
Allen P. Burke, MD and
Jeffrey R. Galvin, MD
1 From the Department of Radiology, U.S. Naval Hospital Roosevelt Roads, Puerto Rico, PSC 1008, Box 177, FPO, AA 34051-3007 (M.L.G.); Departments of Radiologic Pathology (M.L.R., J.R.G.) and Cardiovascular Pathology (A.P.B.), Armed Forces Institute of Pathology, Washington, DC; Department of Radiology and Nuclear Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md (M.L.R.); and Department of Radiology, Georgetown University Hospital, Washington, DC (C.E.G.). Received October 19, 2001; revision requested December 12 and received January 3, 2002; accepted January 7. Address correspondence to M.L.G. (e-mail: mlgrebenc@rroads.med.navy.mil).
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Abstract
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Eighty-six cardiac myxomas were reviewed retrospectively for the clinical, pathologic, and radiologic findings. In this series, 83 patients (47 female and 36 male; age range, 2–78 years; mean age, 48 years) had 49 left atrial (60%), 23 right atrial (28%), seven right ventricular (8%), two biatrial, and two cases of multifocal myxomas. Seventy-one (88%) patients were symptomatic. Radiographs of 38 patients with left atrial myxoma showed evidence of mitral valve obstruction in 53%; radiographs of 16 patients with right atrial myxoma demonstrated calcification and cardiomegaly in 56% and 50%, respectively. Computed tomographic (CT) scans of 21 myxomas demonstrated 20 (95%) spherical or ovoid lesions, 16 (76%) with lobular borders. Seventeen (81%) were hypoattenuated; 14 (67%) were heterogeneous. Twenty-eight magnetic resonance (MR) imaging studies of 30 myxomas showed 29 (97%) spherical or ovoid lesions; 26 (87%) had lobular contours and 26 (90%) of 29 had heterogeneous signal intensity on T1-weighted images. Point of attachment was visible in 15 (83%) cases. Cine gradient recalled echo (GRE) MR images of 10 lesions showed low signal intensity in all cases. Most patients with cardiac myxomas have abnormal but usually nonspecific radiographic findings. CT demonstrates intracavitary heterogeneous, hypoattenuated lobular masses. MR imaging shows heterogeneous lobular lesions and usually allows visualization of the point of attachment. Radiologic imaging of these lesions, particularly with multiplanar and cine GRE MR imaging, can provide accurate assessment of the size, location, and point of attachment of these lesions and should assist in surgical planning.
© RSNA, 2002
Index Terms: Carney complex, 52.19699 • Heart, neoplasms, 52.311 • Myxoma, 52.311
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LEARNING OBJECTIVES FOR TEST 6
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After reading this article and taking the test, the reader will be able to:
- Describe the typical clinical presentation of a large series of cardiac myxomas.
- Enumerate classic radiologic features of cardiac myxoma.
- Define the underlying gross and microscopic characteristics of cardiac myxoma that result in its imaging appearance.
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Introduction
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Cardiac myxoma is a benign neoplasm that represents the most common primary tumor of the heart. Myxoma typically manifests as a polypoid, intracavitary left atrial mass that arises from the interatrial septum, but it may originate in any cardiac chamber (1,2). Although most cases occur sporadically, familial lesions and lesions associated with a clinical complex have also been reported (3,4). Most affected patients present with at least one feature of a classically described triad that includes cardiac obstructive symptoms, constitutional symptoms, and embolic events (5). Because the clinical presentation of patients with cardiac myxomas is diverse and nonspecific, imaging plays a key role in establishing the diagnosis. The radiologic features of cardiac myxomas have been described in several small series and reports (6–12). We present the imaging characteristics of 86 cardiac myxomas in 83 patients and correlate them with clinical and pathologic features.
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Materials and Methods
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A retrospective review of 99 proved cases of cardiac myxoma referred to the Armed Forces Institute of Pathology between 1955 and 1998 was performed. Eighty-three of these patients with a total of 86 myxomas were evaluated with either chest radiography, computed tomography (CT), or magnetic resonance (MR) imaging, and this group formed the basis for this study. There were 62 chest radiography examinations, 28 MR imaging studies, and 19 chest CT examinations. Forty-two patients were imaged with only radiography, 11 with only MR imaging, and six with only CT. Eleven patients were imaged with radiography and MR imaging; seven with radiography and CT; four with CT and MR imaging; and two with radiography, CT, and MR imaging.
Clinical histories were reviewed, noting age, gender, and clinical presentation. Surgical and pathologic reports were reviewed to determine tumor location, tumor size, point of attachment, and gross and microscopic findings. The diagnosis of cardiac myxoma was confirmed in every case by an experienced cardiovascular pathologist through evaluation of resected tissues.
All chest radiographs were reviewed by three radiologists (M.L.G, M.L.R., C.E.G) and coded by consensus. Presence or absence of signs of elevated left atrial pressure, left atrial enlargement, intracardiac (tumoral) calcification, and cardiomegaly were noted as well as associated radiographic abnormalities.
Chest CT scans were reviewed by two radiologists (M.L.G, M.L.R.) and coded by consensus. Because the patients in this series were imaged in multiple institutions with a variety of scanners, CT techniques varied. Fifteen studies were performed after and four before and after the intravenous administration of contrast material.
Cardiac MR imaging studies were reviewed by three radiologists (M.L.G, M.L.R., C.E.G) and coded by consensus. The MR images were obtained on a variety of imaging systems with various combinations of axial, coronal, and sagittal planes. T1-weighted spin-echo images were available in 27 cases, 16 with only T1-weighted and 11 with T1-weighted and T2-weighted or cine gradient recalled echo (GRE) images. One case was imaged only with cine GRE MR imaging. Six T1-weighted MR imaging studies were performed before and after intravenous administration of gadolinium.
All images were evaluated to determine tumor location, shape, and contour; tumor attenuation or signal intensity with respect to the myocardium; enhancement characteristics; visualization of the point of contact of the tumor with the chamber wall; presence of calcification; and demonstration of tumor prolapse across the atrioventricular valve.
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Results
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Patients and Clinical Presentation
There were 47 female patients and 36 male patients who ranged in age from 2 to 78 years (mean, 48 years). Five of these patients (four male and one female) had atypical myxomas, including multiple, recurrent, or familial myxomas or myxoma associated with the Carney complex. The latter group ranged in age from 19 to 48 years (mean, 32 years). Clinical data were available for 81 of 83 patients and are presented according to tumor location (Table). Seventy-one patients presented with symptoms or signs, 37 had more than one symptom or sign, and 10 were asymptomatic.
Surgical Findings
Surgical reports were available in 42 cases (21 left atrial, 16 right atrial, four right ventricular, and one biatrial). Surgical resection was performed in all patients and was complete in 40 cases. Twelve (57%) left atrial myxomas arose from the fossa ovalis of the interatrial septum, seven (33%) from the atrial free wall, one from the anterior leaflet of the mitral valve, and one from the atrial septum and the atrial free wall. Ten (63%) right atrial myxomas arose from the fossa ovalis, three (19%) from the lateral atrial wall, two from the free wall and septum, and one from the coronary sinus. One right ventricular myxoma arose from the right ventricular outflow tract, one arose from the ventricular free wall, and two were adherent to the tricuspid valve with extensive involvement of the ventricular wall. The single case of biatrial myxoma arose from both sides of the fossa ovalis.
Pathologic Findings
There were 49 left atrial (59%), 23 right atrial (28%), seven right ventricular (8%), two biatrial (single mass that grows on both sides of the fossa ovalis of the interatrial septum), and two multichamber myxomas (one case with left atrial, right atrial, and right ventricular myxomas and one case with left atrial and right ventricular myxomas). There were no left ventricular myxomas. Tumor measurement was described in 64 cases and ranged from 2.0 to 11.0 cm in longest dimension (mean, 5.8 cm).
Detailed pathologic reports were available in 62 cases, including 62 external surface gross descriptions and 62 cut surface or microscopic descriptions (37 had both cut surface and microscopic descriptions, 13 had only cut surface, and 12 had only microscopic). Contour was described for 43 tumors; 22 (51%) were lobular, 14 (33%) were smooth, and seven (16%) were frondlike or irregular (Fig 1). Consistency was described for 44 tumors; 31 (70%) were soft, gelatinous, or friable; eight (18%) were firm; and five (11%) were mixed, with both soft and firm areas. Focal hemorrhage (Fig 1a), heme-laden macrophages, thrombus, or hemosiderin (Fig 2) were described in gross or microscopic descriptions in 50 (81%) cases, and calcification (Fig 2b) or ossification were described in 35 (56%) of 62 myxomas. Cystic change was described in seven (14%) of 50 cut surface reports. Microscopic fibrosis was described in eight (16%) and necrosis in three (6%) of 49 microscopic reports. Correlation of the chamber of origin with the presence of macroscopic or microscopic calcification or ossification revealed that 15 of 23 (65%) right atrial, 17 of 30 (57%) left atrial, and three of six (50%) right ventricular myxomas contained calcification or ossification.
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Figure 1a. Gross features of cardiac myxoma. (a) Photograph of a gross specimen demonstrates an ovoid, lobular mass with surface foci of hemorrhage. Note the pedicle (arrow), which attached this left atrial myxoma to the endocardium of the interatrial septum. (b) Photograph of the cut surface of a cardiac myxoma demonstrates a smooth inner contour (arrow).
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Figure 1b. Gross features of cardiac myxoma. (a) Photograph of a gross specimen demonstrates an ovoid, lobular mass with surface foci of hemorrhage. Note the pedicle (arrow), which attached this left atrial myxoma to the endocardium of the interatrial septum. (b) Photograph of the cut surface of a cardiac myxoma demonstrates a smooth inner contour (arrow).
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Figure 2a. Microscopic features of cardiac myxoma. (a) Intermediate magnification photomicrograph (hematoxylin-eosin stain) demonstrates numerous hemosiderin-laden macrophages (arrows) indicating prior hemorrhage. (b) Intermediate magnification photomicrograph (hematoxylin-eosin stain) demonstrates calcified elastic fibers (black staining structures), often called gamna bodies. Calcification in myxoma may occur in various forms. Acute hemorrhage (arrowhead) is present as well.
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Figure 2b. Microscopic features of cardiac myxoma. (a) Intermediate magnification photomicrograph (hematoxylin-eosin stain) demonstrates numerous hemosiderin-laden macrophages (arrows) indicating prior hemorrhage. (b) Intermediate magnification photomicrograph (hematoxylin-eosin stain) demonstrates calcified elastic fibers (black staining structures), often called gamna bodies. Calcification in myxoma may occur in various forms. Acute hemorrhage (arrowhead) is present as well.
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Imaging Findings
Chest Radiography.—
Sixty-two patients were imaged with chest radiography. Radiographs of 38 patients with left atrial myxomas showed evidence of elevated left atrial pressure in 20 (53%) and cardiomegaly in 14 (37%). Specific findings related to elevated left atrial pressure included left atrial enlargement in 13 cases (Fig 3), vascular redistribution in 10, prominent pulmonary trunk in six, pulmonary edema in four, and enlarged left atrial appendage in two (Fig 4). Pleural effusions were noted in six cases and intracardiac tumoral calcification in one. Fourteen (37%) chest radiographs had normal findings.
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Figure 3a. Left atrial myxoma in a 62-year-old woman with a long history of heart failure and a murmur of mitral insufficiency. (a, b) Posteroanterior (a) and lateral (b) chest radiographs obtained after barium ingestion demonstrate massive cardiomegaly and left atrial enlargement with resultant mass effect on the contrast material-filled esophagus (arrows). Note prominent atrial appendage. (c) Photograph of the gross specimen demonstrates a lobular heterogeneous mass with foci of hemorrhage.
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Figure 3b. Left atrial myxoma in a 62-year-old woman with a long history of heart failure and a murmur of mitral insufficiency. (a, b) Posteroanterior (a) and lateral (b) chest radiographs obtained after barium ingestion demonstrate massive cardiomegaly and left atrial enlargement with resultant mass effect on the contrast material-filled esophagus (arrows). Note prominent atrial appendage. (c) Photograph of the gross specimen demonstrates a lobular heterogeneous mass with foci of hemorrhage.
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Figure 3c. Left atrial myxoma in a 62-year-old woman with a long history of heart failure and a murmur of mitral insufficiency. (a, b) Posteroanterior (a) and lateral (b) chest radiographs obtained after barium ingestion demonstrate massive cardiomegaly and left atrial enlargement with resultant mass effect on the contrast material-filled esophagus (arrows). Note prominent atrial appendage. (c) Photograph of the gross specimen demonstrates a lobular heterogeneous mass with foci of hemorrhage.
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Figure 4a. Left atrial myxoma in a 33-year-old woman with a history of fatigue, dyspnea, syncope, and a pansystolic murmur. Posteroanterior (a) and lateral (b) chest radiographs demonstrate left atrial enlargement, prominence of the left atrial appendage (arrow), and pulmonary vascular redistribution.
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Figure 4b. Left atrial myxoma in a 33-year-old woman with a history of fatigue, dyspnea, syncope, and a pansystolic murmur. Posteroanterior (a) and lateral (b) chest radiographs demonstrate left atrial enlargement, prominence of the left atrial appendage (arrow), and pulmonary vascular redistribution.
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Sixteen patients with right atrial myxomas underwent chest radiography. Visible intracardiac calcification was present in nine (56%) cases and cardiomegaly in eight (50%). Both cardiomegaly and intracardiac calcification were seen in five (31%) cases (Fig 5). Additional findings included pleural effusions in four cases and multifocal lung opacities consistent with septic emboli in one. Five (31%) chest radiographs had normal findings.
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Figure 5a. Right atrial myxoma in a 68-year-old woman with sick sinus syndrome. (a, b) Posteroanterior (a) and lateral (b) chest radiographs demonstrate dense, coarse, curvilinear tumoral calcification projecting over the right atrium (arrow) and cardiomegaly. (c) Photograph of the resected 4.5-cm right atrial myxoma demonstrates a calcified area on the surface (arrowhead). The pathologist commented that the specimen was extremely firm and required a band saw for section.
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Figure 5b. Right atrial myxoma in a 68-year-old woman with sick sinus syndrome. (a, b) Posteroanterior (a) and lateral (b) chest radiographs demonstrate dense, coarse, curvilinear tumoral calcification projecting over the right atrium (arrow) and cardiomegaly. (c) Photograph of the resected 4.5-cm right atrial myxoma demonstrates a calcified area on the surface (arrowhead). The pathologist commented that the specimen was extremely firm and required a band saw for section.
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Figure 5c. Right atrial myxoma in a 68-year-old woman with sick sinus syndrome. (a, b) Posteroanterior (a) and lateral (b) chest radiographs demonstrate dense, coarse, curvilinear tumoral calcification projecting over the right atrium (arrow) and cardiomegaly. (c) Photograph of the resected 4.5-cm right atrial myxoma demonstrates a calcified area on the surface (arrowhead). The pathologist commented that the specimen was extremely firm and required a band saw for section.
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Of the five chest radiographs in patients with right ventricular myxomas, two had normal findings, two showed cardiomegaly, and one showed a right pleural effusion. Radiographs of the two patients with biatrial myxomas showed multifocal nodular parenchymal opacities and a pleural-based opacity consistent with a pulmonary infarct in one (Fig 6a) and left atrial enlargement in one. One radiograph of a patient with multichamber myxomas demonstrated cardiomegaly.
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Figure 6a. Pulmonary infarct in a 19-year-old woman with a biatrial myxoma who presented with cough, hemoptysis, and abdominal pain. (a) Posteroanterior chest radiograph demonstrates multifocal parenchymal nodular opacities and a large pleural-based opacity in the left lower lobe. (b, c) Contrast material-enhanced chest CT scans (b, mediastinal window, and c, lung window) demonstrate a subtle low-attenuation mass in the right atrium, mosaic perfusion, angiocentric nodules, and wedge-shaped areas of low attenuation in the left lower lobe consistent with pulmonary infarcts.
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Figure 6b. Pulmonary infarct in a 19-year-old woman with a biatrial myxoma who presented with cough, hemoptysis, and abdominal pain. (a) Posteroanterior chest radiograph demonstrates multifocal parenchymal nodular opacities and a large pleural-based opacity in the left lower lobe. (b, c) Contrast material-enhanced chest CT scans (b, mediastinal window, and c, lung window) demonstrate a subtle low-attenuation mass in the right atrium, mosaic perfusion, angiocentric nodules, and wedge-shaped areas of low attenuation in the left lower lobe consistent with pulmonary infarcts.
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Figure 6c. Pulmonary infarct in a 19-year-old woman with a biatrial myxoma who presented with cough, hemoptysis, and abdominal pain. (a) Posteroanterior chest radiograph demonstrates multifocal parenchymal nodular opacities and a large pleural-based opacity in the left lower lobe. (b, c) Contrast material-enhanced chest CT scans (b, mediastinal window, and c, lung window) demonstrate a subtle low-attenuation mass in the right atrium, mosaic perfusion, angiocentric nodules, and wedge-shaped areas of low attenuation in the left lower lobe consistent with pulmonary infarcts.
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Pathologic reports were available in 44 of the 62 cases imaged with chest radiography. Although the reports in 26 cases described tumoral calcification or ossification (13 left atrial, 11 right atrial, and two right ventricular), calcification was exhibited at radiography in only eight cases, all of which were right atrial myxomas.
Computed Tomography.—
Twenty-one myxomas (including one case of multichamber myxoma) were evaluated with 19 CT studies. Twenty myxomas (95%) were spherical or ovoid and one was triangular. Sixteen (76%) had a lobular contour and five (24%) were smooth (Fig 7). Contrast-enhanced chest CT showed 17 (81%) myxomas with an overall attenuation lower than that of myocardium (Fig 7) and four (19%) with equal attenuation. There were no high-attenuation (relative to myocardium) myxomas. Fourteen (67%) myxomas were heterogeneous, seven (33%) were homogeneous, and three (14%) contained coarse or punctate calcification (Fig 8). Three of four myxomas (evaluated before and after administration of contrast material) demonstrated heterogeneous enhancement (Figs 7–10). The point of contact of the tumor with the cardiac chamber wall was evaluated in all 21 myxomas, and surgical correlation was available in 10. In only three (30%) cases did the point of attachment as described surgically match the CT finding (Fig 7). Enlargement of the affected cardiac chamber was seen in eight (38%) cases (Figs 7, 8, 10).
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Figure 7a. Left atrial myxoma in a 71-year-old woman with progressive dyspnea. Contrast-enhanced chest CT scans (mediastinal window, a obtained at a higher level than b) demonstrate an ovoid, smooth, heterogeneous left atrial mass with internal foci of enhancement. Note the left atrial enlargement and dilated pulmonary veins (arrows in b). The point of attachment appears to be the interatrial septum. This finding was confirmed at surgery.
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Figure 7b. Left atrial myxoma in a 71-year-old woman with progressive dyspnea. Contrast-enhanced chest CT scans (mediastinal window, a obtained at a higher level than b) demonstrate an ovoid, smooth, heterogeneous left atrial mass with internal foci of enhancement. Note the left atrial enlargement and dilated pulmonary veins (arrows in b). The point of attachment appears to be the interatrial septum. This finding was confirmed at surgery.
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Figure 8a. Right atrial myxoma in a 52-year-old woman with shoulder pain in whom the myxoma was incidentally found during MR imaging of the scapula. (a) Contrast-enhanced chest CT scan (mediastinal window) shows an ovoid, hypoattenuated, heterogeneous, right atrial mass with multifocal coarse calcifications. (b) Delayed chest CT scan (mediastinal window) helps confirm the coarse tumoral calcifications. (c) Photograph of the cut surface of the resected specimen demonstrates a heterogeneous lesion with myxoid areas interspersed amid hemorrhagic areas.
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Figure 8b. Right atrial myxoma in a 52-year-old woman with shoulder pain in whom the myxoma was incidentally found during MR imaging of the scapula. (a) Contrast-enhanced chest CT scan (mediastinal window) shows an ovoid, hypoattenuated, heterogeneous, right atrial mass with multifocal coarse calcifications. (b) Delayed chest CT scan (mediastinal window) helps confirm the coarse tumoral calcifications. (c) Photograph of the cut surface of the resected specimen demonstrates a heterogeneous lesion with myxoid areas interspersed amid hemorrhagic areas.
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Figure 8c. Right atrial myxoma in a 52-year-old woman with shoulder pain in whom the myxoma was incidentally found during MR imaging of the scapula. (a) Contrast-enhanced chest CT scan (mediastinal window) shows an ovoid, hypoattenuated, heterogeneous, right atrial mass with multifocal coarse calcifications. (b) Delayed chest CT scan (mediastinal window) helps confirm the coarse tumoral calcifications. (c) Photograph of the cut surface of the resected specimen demonstrates a heterogeneous lesion with myxoid areas interspersed amid hemorrhagic areas.
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Figure 9a. Right ventricular myxoma in a 19-year-old man who presented with fever, dyspnea, and peripheral edema. (a) Unenhanced chest CT scan (mediastinal window) demonstrates a large hypoattenuated lobular mass (m) that entirely fills the right ventricle. Note right atrial (RA) enlargement and large right pleural and small pericardial effusions. (b) Contrast-enhanced chest CT scan (mediastinal window) shows heterogeneous enhancement of the right ventricular mass. (c) Contrast-enhanced abdominal CT scan (soft-tissue window) demonstrates ascites and mottled hepatic enhancement, consistent with passive congestion.
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Figure 9b. Right ventricular myxoma in a 19-year-old man who presented with fever, dyspnea, and peripheral edema. (a) Unenhanced chest CT scan (mediastinal window) demonstrates a large hypoattenuated lobular mass (m) that entirely fills the right ventricle. Note right atrial (RA) enlargement and large right pleural and small pericardial effusions. (b) Contrast-enhanced chest CT scan (mediastinal window) shows heterogeneous enhancement of the right ventricular mass. (c) Contrast-enhanced abdominal CT scan (soft-tissue window) demonstrates ascites and mottled hepatic enhancement, consistent with passive congestion.
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Figure 9c. Right ventricular myxoma in a 19-year-old man who presented with fever, dyspnea, and peripheral edema. (a) Unenhanced chest CT scan (mediastinal window) demonstrates a large hypoattenuated lobular mass (m) that entirely fills the right ventricle. Note right atrial (RA) enlargement and large right pleural and small pericardial effusions. (b) Contrast-enhanced chest CT scan (mediastinal window) shows heterogeneous enhancement of the right ventricular mass. (c) Contrast-enhanced abdominal CT scan (soft-tissue window) demonstrates ascites and mottled hepatic enhancement, consistent with passive congestion.
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Figure 10a. Right atrial myxoma in a 51-year-old woman with abdominal complaints. (a) Contrast-enhanced chest CT scan (mediastinal window) shows a lobular, heterogeneous right atrial mass with foci of internal calcification, heterogeneous enhancement, and right atrial enlargement. (b) Another CT scan obtained at a lower level shows the mass, which extends caudally into an enlarged inferior vena cava. (c) Photograph of the gross specimen shows the lobular, variegated, hemorrhagic, ovoid mass.
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Figure 10b. Right atrial myxoma in a 51-year-old woman with abdominal complaints. (a) Contrast-enhanced chest CT scan (mediastinal window) shows a lobular, heterogeneous right atrial mass with foci of internal calcification, heterogeneous enhancement, and right atrial enlargement. (b) Another CT scan obtained at a lower level shows the mass, which extends caudally into an enlarged inferior vena cava. (c) Photograph of the gross specimen shows the lobular, variegated, hemorrhagic, ovoid mass.
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Figure 10c. Right atrial myxoma in a 51-year-old woman with abdominal complaints. (a) Contrast-enhanced chest CT scan (mediastinal window) shows a lobular, heterogeneous right atrial mass with foci of internal calcification, heterogeneous enhancement, and right atrial enlargement. (b) Another CT scan obtained at a lower level shows the mass, which extends caudally into an enlarged inferior vena cava. (c) Photograph of the gross specimen shows the lobular, variegated, hemorrhagic, ovoid mass.
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Additional associated findings were present in eight cases. These included pleural effusion in two cases (Fig 9); tumor extension into the inferior vena cava in two cases (Fig 10b); and one case each of tumor extension into the superior vena cava, pulmonary infarcts (Fig 6b, Fig 6c), tumor embolus in the abdominal aorta (with associated renal and splenic infarcts) (Fig 10), and tricuspid valve obstruction (with accumulation of contrast material in the right atrium, ascites, liver congestion, soft-tissue edema, and pericardial effusion) (Fig 9).
MR Imaging.—
Thirty myxomas were evaluated with 28 MR imaging studies. Twenty-nine (97%) were spherical or ovoid and one was irregular in shape. Twenty-six (87%) tumors had lobular contours (Fig 11) and four (13%) were smooth. Relative signal intensity could not be evaluated in a single case as only GRE imaging was performed. Twenty-six (90%) of 29 myxomas were of heterogeneous signal intensity (Figs 11 –13) and three were homogeneous; 23 (79%) were predominantly isointense (Figs 11, 13), four (14%) were hyperintense (Fig 14), and two were hypointense with respect to the myocardium on T1-weighted images.
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Figure 11a. Left atrial myxoma in a 41-year-old patient with dyspnea on exertion. (a) Sagittal T1-weighted (repetition time msec/echo time msec = 938/18) MR image demonstrates a heterogeneous mass within the left atrium. Note left atrial enlargement. (b) Axial proton-density-weighted (2127/18) MR image demonstrates increased signal intensity in the mass and an internal low-signal-intensity focus. (c) Axial T2-weighted (2,727/80) MR image shows very bright signal intensity throughout most of the tumor and peripheral foci of low signal intensity. (d) Photograph of the gross specimen demonstrates the lobular heterogeneous pedunculated myxoma.
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Figure 11b. Left atrial myxoma in a 41-year-old patient with dyspnea on exertion. (a) Sagittal T1-weighted (repetition time msec/echo time msec = 938/18) MR image demonstrates a heterogeneous mass within the left atrium. Note left atrial enlargement. (b) Axial proton-density-weighted (2127/18) MR image demonstrates increased signal intensity in the mass and an internal low-signal-intensity focus. (c) Axial T2-weighted (2,727/80) MR image shows very bright signal intensity throughout most of the tumor and peripheral foci of low signal intensity. (d) Photograph of the gross specimen demonstrates the lobular heterogeneous pedunculated myxoma.
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Figure 11c. Left atrial myxoma in a 41-year-old patient with dyspnea on exertion. (a) Sagittal T1-weighted (repetition time msec/echo time msec = 938/18) MR image demonstrates a heterogeneous mass within the left atrium. Note left atrial enlargement. (b) Axial proton-density-weighted (2127/18) MR image demonstrates increased signal intensity in the mass and an internal low-signal-intensity focus. (c) Axial T2-weighted (2,727/80) MR image shows very bright signal intensity throughout most of the tumor and peripheral foci of low signal intensity. (d) Photograph of the gross specimen demonstrates the lobular heterogeneous pedunculated myxoma.
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Figure 11d. Left atrial myxoma in a 41-year-old patient with dyspnea on exertion. (a) Sagittal T1-weighted (repetition time msec/echo time msec = 938/18) MR image demonstrates a heterogeneous mass within the left atrium. Note left atrial enlargement. (b) Axial proton-density-weighted (2127/18) MR image demonstrates increased signal intensity in the mass and an internal low-signal-intensity focus. (c) Axial T2-weighted (2,727/80) MR image shows very bright signal intensity throughout most of the tumor and peripheral foci of low signal intensity. (d) Photograph of the gross specimen demonstrates the lobular heterogeneous pedunculated myxoma.
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Figure 12a. Left atrial myxoma in a 60-year-old man with dyspnea. (a) Axial T1-weighted (845/25) MR image demonstrates an ovoid, smooth, heterogeneous mass attached to the interatrial septum. (b) Axial cine GRE (11/5.4) MR image demonstrates prolapse of the dark mass across the mitral valve (arrowhead).
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Figure 12b. Left atrial myxoma in a 60-year-old man with dyspnea. (a) Axial T1-weighted (845/25) MR image demonstrates an ovoid, smooth, heterogeneous mass attached to the interatrial septum. (b) Axial cine GRE (11/5.4) MR image demonstrates prolapse of the dark mass across the mitral valve (arrowhead).
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Figure 13a. Right atrial myxoma in a 74-year-old woman with a history of weight loss and heart failure. (a, b) Axial (a) and coronal (b) T1-weighted (600/80) MR images demonstrate a spherical, heterogeneous right atrial mass. (c) Coronal cine GRE (27/18) MR image shows near complete loss of signal intensity within the tumor and the point of attachment to the interatrial septum (arrow). (d) Photograph of the resected specimen demonstrates the lobular tumor and its point of endocardial attachment (arrowhead).
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Figure 13b. Right atrial myxoma in a 74-year-old woman with a history of weight loss and heart failure. (a, b) Axial (a) and coronal (b) T1-weighted (600/80) MR images demonstrate a spherical, heterogeneous right atrial mass. (c) Coronal cine GRE (27/18) MR image shows near complete loss of signal intensity within the tumor and the point of attachment to the interatrial septum (arrow). (d) Photograph of the resected specimen demonstrates the lobular tumor and its point of endocardial attachment (arrowhead).
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Figure 13c. Right atrial myxoma in a 74-year-old woman with a history of weight loss and heart failure. (a, b) Axial (a) and coronal (b) T1-weighted (600/80) MR images demonstrate a spherical, heterogeneous right atrial mass. (c) Coronal cine GRE (27/18) MR image shows near complete loss of signal intensity within the tumor and the point of attachment to the interatrial septum (arrow). (d) Photograph of the resected specimen demonstrates the lobular tumor and its point of endocardial attachment (arrowhead).
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Figure 13d. Right atrial myxoma in a 74-year-old woman with a history of weight loss and heart failure. (a, b) Axial (a) and coronal (b) T1-weighted (600/80) MR images demonstrate a spherical, heterogeneous right atrial mass. (c) Coronal cine GRE (27/18) MR image shows near complete loss of signal intensity within the tumor and the point of attachment to the interatrial septum (arrow). (d) Photograph of the resected specimen demonstrates the lobular tumor and its point of endocardial attachment (arrowhead).
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Figure 14a. Left atrial myxoma in a 61-year-old woman with chest pain. (a) Axial T1-weighted (938/20) MR image demonstrates a round, lobular, heterogeneous mass (arrowhead) attached to the interatrial septum. The focal bright areas are consistent with chronic hemorrhage. (b) Photograph of the cut surface of the resected myxoma shows a grossly hemorrhagic mass, which microscopically contained hemorrhage and hemosiderin-laden macrophages.
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Figure 14b. Left atrial myxoma in a 61-year-old woman with chest pain. (a) Axial T1-weighted (938/20) MR image demonstrates a round, lobular, heterogeneous mass (arrowhead) attached to the interatrial septum. The focal bright areas are consistent with chronic hemorrhage. (b) Photograph of the cut surface of the resected myxoma shows a grossly hemorrhagic mass, which microscopically contained hemorrhage and hemosiderin-laden macrophages.
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All six myxomas evaluated after intravenous gadolinium administration demonstrated enhancement (Fig 15) (heterogeneous in four and homogeneous in two). The point of contact of the tumor with the cardiac chamber wall was evaluated in all 30 myxomas, and surgical correlation was available in 18. In 15 (83%) cases, the site of tumor attachment described surgically correlated with the point of contact identified at MR imaging (Figs 11–13).
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Figure 15a. Right atrial myxoma in a 47-year-old woman with prominent neck vein pulsations, fatigue, and headache. (a) Coronal T1-weighted (869/20) MR image demonstrates a spherical heterogeneous mass attached to the lateral wall of the right atrium. (b) Axial proton-density-weighted (2,666/10) MR image demonstrates prolapse of the tumor across the tricuspid valve. (c) Axial T1-weighted (722/20) gadolinium-enhanced MR image demonstrates heterogeneous central foci of enhancement in the myxoma.
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Figure 15b. Right atrial myxoma in a 47-year-old woman with prominent neck vein pulsations, fatigue, and headache. (a) Coronal T1-weighted (869/20) MR image demonstrates a spherical heterogeneous mass attached to the lateral wall of the right atrium. (b) Axial proton-density-weighted (2,666/10) MR image demonstrates prolapse of the tumor across the tricuspid valve. (c) Axial T1-weighted (722/20) gadolinium-enhanced MR image demonstrates heterogeneous central foci of enhancement in the myxoma.
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Figure 15c. Right atrial myxoma in a 47-year-old woman with prominent neck vein pulsations, fatigue, and headache. (a) Coronal T1-weighted (869/20) MR image demonstrates a spherical heterogeneous mass attached to the lateral wall of the right atrium. (b) Axial proton-density-weighted (2,666/10) MR image demonstrates prolapse of the tumor across the tricuspid valve. (c) Axial T1-weighted (722/20) gadolinium-enhanced MR image demonstrates heterogeneous central foci of enhancement in the myxoma.
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Ten myxomas were evaluated with cine GRE imaging. All demonstrated low signal intensity and four prolapsed across the atrioventricular valve (Fig 12b) (one additional case of tumor prolapse was identified on spin-echo MR images). The four myxomas that were evaluated with both T1- and T2-weighted pulse sequences demonstrated heterogeneous increase in signal intensity on T2-weighted images (Fig 11). Chamber enlargement was visualized in seven (23%) of 30 myxomas; the chamber of origin was enlarged in five cases (Fig 11) and a different chamber was enlarged in two.
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Discussion
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Myxoma is the most common primary cardiac neoplasm and accounts for approximately one-half of all primary cardiac tumors (1). Because of the nonspecific clinical presentation of patients with cardiac myxomas, premortem diagnosis was not accomplished until 1952, when Goldberg et al (13) demonstrated a left atrial myxoma at cardiac angiography. The first successful surgical resection of a cardiac myxoma was performed with a cardiopulmonary bypass in 1954, and this patient was still alive in 1997 (14,15).
In concurrence with our series, patients with cardiac myxomas are reported to have a wide age range (15–80 years), with a mean age of approximately 50 years. There appears to be a slight female predominance, with a female-to-male ratio of 5:4 (1,5,15–17). Sixty-seven (83%) of our patients presented with at least one manifestation of a classically described clinical triad, which includes cardiac obstructive symptoms, embolic phenomena, and constitutional symptoms (5).
Presenting complaints relate to tumor location, which predicts obstructive sequelae and influences embolic sites (pulmonary or systemic). Left atrial myxomas commonly cause mitral valve obstruction, and symptoms mimic those of rheumatic heart disease. Affected patients present with dyspnea and orthopnea from pulmonary venous hypertension (1,5,15). The pedunculated and prolapsing nature of these tumors allows for positional and intermittent mitral valve obstruction. In our series, 60% of patients with left atrial myxomas presented with symptoms related to mitral valve obstruction. Right atrial myxomas may obstruct the tricuspid valve and cause symptoms of right-sided heart failure, peripheral edema, passive hepatic congestion, and syncope. In our series, only 9% of patients with right atrial myxomas presented with signs and symptoms of tricuspid valve obstruction. Ventricular myxomas may also cause right-sided heart obstruction, which was seen in one of seven patients in our series (1,5).
Constitutional symptoms of fever, malaise, weight loss, anemia, and elevated sedimentation rate have been reported and may be related to an autoimmune reaction initiated by the tumor (1,5,8,18). These symptoms were present in 32% of our patients. Cardiac arrhythmias, atrial fibrillation, and atrial flutter reportedly occur in approximately 20% of patients with cardiac myxoma (16,19). In our series, 16% of patients presented with arrhythmia or palpitations. Embolic phenomena are reported in approximately 35% of left-sided and 10% of right-sided myxomas (1,15,19,20). The propensity of cardiac myxomas to embolize is thought to be related to tumor morphology, with friable and gelatinous myxomas being more likely to embolize than firm and fibrous lesions (1,20,21). Left-sided myxomas embolize systemically, usually to the brain, kidneys, and lower extremities, and right-sided myxomas embolize to the pulmonary circulation (1,15,19). Eight (17%) of 47 patients with left atrial myxomas in our series (in whom clinical history was available) presented with systemic embolization (Fig 16); in addition, one patient with a right ventricular myxoma and one with a biatrial myxoma manifested with pulmonary embolism (Fig 6). However, five patients with emboli from left-sided myxomas not included in our series of 83 patients because imaging of only the embolic sequelae and not of the cardiac myxomas was performed. Approximately 20% of all patients with myxomas irrespective of intracardiac location are reportedly asymptomatic, and the tumors are discovered incidentally or at autopsy (22). This was the case in 12% of our patients.
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Figure 16a. Cardiac myxoma embolism in a 35-year-old woman who presented with acute right flank pain, anemia, recurrent fever, and malaise. (a) Right renal artery arteriogram demonstrates an elongate filling defect in an interlobar renal artery (arrows). (b) Photograph of the cut specimen from the partial nephrectomy shows areas of hemorrhagic infarction and necrosis.
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Figure 16b. Cardiac myxoma embolism in a 35-year-old woman who presented with acute right flank pain, anemia, recurrent fever, and malaise. (a) Right renal artery arteriogram demonstrates an elongate filling defect in an interlobar renal artery (arrows). (b) Photograph of the cut specimen from the partial nephrectomy shows areas of hemorrhagic infarction and necrosis.
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The majority of cardiac myxomas occur sporadically. However, in approximately 7% of patients, cardiac myxomas exhibit atypical behavior, demonstrating a familial predisposition or an association with a clinical complex (Carney complex). These patients tend to be younger (mean age, 24 years) and male, and the myxomas are more likely to be multicentric (45%) or recurrent (12%–22%), whereas only 1%–3% of sporadic myxomas reportedly recur (3,4,23,24). Carney complex is an autosomal dominant condition with a complex of lesions that include mammary myxoid fibroadenoma, spotty pigmented lesions of the skin, endocrine disorders, testicular tumors, and psammomatous melanotic schwannoma. Two-thirds of these patients have cardiac myxomas (23,24). In our series, five (6%) patients had multiple, recurrent, or familial myxomas and one had the Carney complex.
Cardiac myxoma is an intracavitary, round or ovoid neoplasm that is attached to the endocardium. Although the vast majority attach at the fossa ovalis of the interatrial septum, they can arise from any endocardial surface (1). The majority (75%) occur in the left atrium, with a smaller proportion in the right atrium (20%) and rare cases in right ventricular, biatrial, left ventricular, or multiple locations (1,15,25). In our series, approximately two-thirds of the atrial myxomas were attached to the interatrial septum, and the tumor location differed slightly from most reports, with 60% arising from the left atrium and 28% from the right atrium.
The histologic features of cardiac myxomas are distinctive but heterogeneous. The once-held theory that myxoma is a form of organizing thrombus has largely been discarded. The cell of origin is unknown, but it is likely a primitive mesenchymal cell capable of diverse forms of differentiation. The tumor cells form rings, nests, and linear syncytia (Fig 17). The amount of myxomatous stroma is widely variable. Hemorrhage, thrombus, and hemosiderin are common and were present in 81% of tumors in our series. Calcification is also common (1,26) and was described in 56% of the pathologic reports in our series.
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Figure 17. Typical microscopic features of cardiac myxoma. Intermediate magnification photomicrograph (hematoxylin-eosin stain) demonstrates nests of myxoma cells (arrows) amid a myxoid matrix (m).
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To our knowledge, this is the largest series describing the chest radiographic manifestations of patients with cardiac myxomas. It verifies the classic radiographic findings of mitral valve obstruction in patients with left atrial myxomas, which were present in 53% of our cases. Other nonspecific manifestations such as cardiomegaly and pleural effusion occurred in 37% and 15% of our cases, respectively. Thus, the radiographic findings in patients with left atrial myxomas usually suggest more common diseases related to pathologic conditions of the mitral valve. Patients with right atrial myxomas demonstrated calcification and cardiomegaly with approximately equal frequency (56% and 50%, respectively), and pleural effusions were seen in one-fourth of these cases. One-third of all patients in this series had normal chest radiographic findings.
Although only 10% of myxomas are reported to contain fluoroscopically detectable calcification (27), approximately 28% reportedly have pathologically evident calcification or ossification (26). In our series, radiographically visible tumoral calcification was much more common in right atrial lesions. In addition, tumor calcification was seen radiographically in the majority (73%) of right atrial myxomas with pathologic evidence of calcification or ossification. Thus, radiographic visualization of tumoral calcification in the right side of the heart should prompt the radiologist to include myxoma in the differential diagnosis. None of the 13 left atrial myxomas with pathologic calcification or ossification demonstrated it radiographically. Microscopic calcification is less common in left than in right atrial myxomas (26), and our series suggests that when calcification is present in a left atrial myxoma it is not substantial enough to be detected at chest radiography.
Previously described CT characteristics of cardiac myxoma include a lobular contour and heterogeneous attenuation (11). Seventy-six percent of cardiac myxomas in our series were lobular, and 62% were heterogeneous on contrast-enhanced CT scans. Cardiac myxomas generally appeared as filling defects within a contrast material–filled cardiac chamber, and all were either hypoattenuated (81%) or isoattenuated relative to the myocardium. Tsuchiya et al (11) attempted to use CT to prospectively determine the site of attachment of cardiac myxomas in a study of six cases. In this small series, the authors accurately predicted that all lesions were attached to the atrial septum (11). In our series, we had surgical descriptions of the point of attachment in 10 cases, but the assessment of the point of contact as seen at CT correlated positively in only three of the 10 cases. It should be noted that the point of contact of large myxomas that completely or almost completely fill the cardiac chamber (Fig 18) or that are attached to multiple sites might be difficult to determine with CT. Chamber enlargement by cardiac myxomas has not been previously described in the CT literature and was seen in 38% of our cases
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Abstract
LEARNING OBJECTIVES FOR TEST...
