- Email: [email protected]
Diagnostic imagings for primary cardiac fibrosarcoma
International Journal of Cardiology, 39 (1993) 157-161 0 1993 Elsevier Scientific Publishers Ireland Ltd. All rights reserved. 0167-5273/93/$06.00
157
CARD10 01683
Diagnostic imagings for primary cardiac fibrosarcoma Wei-Jen Shih, Scott McCullough and Mary Smith Department of Veterans Affairs Medical Center and University of Kentucky Medical Center, Lexington, KY 40511, USA
(Received 31 July 1992; revision accepted 8 December 1992)
Primary tumors of the heart are rare; primary cardiac fibrosarcoma is even rarer. We report a patient with primary cardiac fibrosarcoma widespread metastases presenting with pulmonary metastases initially. The cardiac lesion was identified by bone-imaging localization on bone scan, by hypodense areas in the cardiac chambers of contrast computed tomography of the chest, and by protruding masses in ventricular cavities causing aortic valve outflow-tract obstruction by echocardiogram. At autopsy, a large tumor invaded the inter-ventricular septum and both ventricular cavities of the heart (880 g in weight), and accounted for these imaging findings. While bone-agent localization in the heart does not differentiate malignant from benign conditions, computed tomography and echocardiography of the interatrial and interventricular septal, and right atria1 and biventricular cavitary involvement may differentiate tibrosarcoma from myxoma. Key words: Primary cardiac fibrosarcoma; Bone imaging agent; Computed tomography; Echocardiogram; Aortic outflow obstruction
Introduction Primary tumors of the heart are rare. Primary cardiac fibrosarcoma is even rarer, [l-5] representing only about 0.3% of cardiac tumors [l-5]. Myocardial librosarcoma is a malignant mesenchymal tumor which is primarily libroblastic in its differentiation [5,6]. It arises with equal frequency in both right and left ventricular walls [l-5]. In about 50% of tibrosarcoma patients, the tumor protrudes into a cardiac chamber, causing signiticant obstruction of a valve orifice [5,6]. Fibrosarcoma of the heart with features of obstruction of the tricuspid valve has been correctly identified by echocardiography [7,8]. Correspondence to: Dr. Wei-Jen Shih, Nuclear Medicine Service, Department of Veterans Affairs Medical Center, Lexington, KY 4051 l-1093, USA.
This report concerns a patient with bulky primary cardiac tibrosarcoma which protruded into ventricular cavities causing aortic valve outflow tract obstruction identified by echocardiogram. In addition, mass lesions of the heart were depicted by computed tomography as well as by bone scintigraphy.
Case Report A 65-year-old man with progressive cough, dyspnea, and chest pain for more than 3 weeks was admitted for workup of nodular lesions in the lungs. He had undergone two coronary artery bypass grafts in 1983. Physical examination showed expiratory wheezes and a II/VI murmur of the heart. Chest radiographs showed multiple nodular lesions. A bone scintigram 3 h after IV injection of 20 mCi Tc-99 m hydroxyl methelene diphosphon-
158
ate showed abnormally increased uptake in the posterior ribs, right acetabulum and left femoral neck; in addition, a mild increase in radioactivity was seen in the cardiac region (Fig. 1). Computed tomography of the chest showed multiple lung nodules, mediastinal lymphadenopathy and contrast media being absent in some of the chambers and parts of the cardiac chambers. Echocardiogram showed an akinetic apex of the left ventricle (LV), a myxomatous lesion on the interventricular septum, a lesion in the left ventricular outflow tract, a right atria1 mass attached to the interatrial septum and a right ventricular mass which obliterated the right ventricular cavity (Fig. 2). Bronchoscopic biopsy and endomycardial biopsies failed to identify any malignancy. An ECG showed ST elevation in the inferior leads suggesting thrombus in the apex of the left ventricle. On the 1ith hospital day, the patient developed spinal cord compression symptoms of lower extremity weakness, numbness, and urinary incontinence. A radiograph of the spine showed a T-9 vertebral compression fracture. To rule out a possibility of infection and metastasis, lumbar puncture and myelogram were attempted, but the patient refused these procedures. Steroids were then given empirically.
On the 14th hospital day the patient died. His immediate cause of death was unrelated to the massive involvement of the heart with tumor. At autopsy, intraplaque hemorrhage with luminal occlusion of the right coronary artery was the most likely antecedent to the patient’s demise. Other autopsy findings included the following: (1) greater tumor mass was in the heart. The heart was enlarged (880 g, with a normal weight of 300-350 g) and contained extensive fleshy, white, soft tumor which occupied the right ventricular free wall, obstructed the RV cavity and replaced the entire apex of the LV (Fig. 3). In addition, a finger-like projection of tumor extended from the LV free wall into the LV outflow tract to the level of the aortic valve. The tumor also invaded the epicardium surrounding the left anterior descending coronary artery, posterior descending coronary artery, and the anastamoses of the patient’s previous coronary artery bypass grafts. (2) Microscopically, primitive spindle-cell tumor infiltrated all four cardiac chambers, and was composed of elongated cells interwoven in a herring-bone pattern. Immunohistological stains demonstrated positivity with vimentin, and negative staining with HMB-45 (for melanoma), S-100, desmin, and muscle-specific actin. Electron microscopy revealed collagen production. This constellation of findings is consistent with fibrosarcoma. (3) Multiple metastases involved the lungs, mediastinal lymph nodes, liver, adrenals, small bowel and bones.
Discussion
Fig. 1. An anterior thoracic scintigraph shows a mild increase in uptake in the region corresponding to the cardiac region (arrows).
Metastatic tumors in the heart are 20-25 times more frequent than primary tumors; [9-l 21 primary cardiac tumors are rare and librosarcoma of the heart is very rare [l-5]. Patients with primary cardiac fibrosarcoma typically have the greatest tumor mass within the heart [5]. About 33% of cardiac fibrosarcomas involve the pericardium [5,6]. In 50-60%, distant metastasis involve the lung [ 131, mediastinal lymph nodes [ 141, vertebrae [15], and brain [4,16]. Our patient’s fibrosarcoma had metastasized to the epicardium, lungs, mediastinal lymph nodes, liver, adrenals, small bowel and bones. Bulky intracardiac tumor accounted for faint
Fig. 2. Echocardiogram shows mass lesions involving the interventricular septum (IVS), right atrium (RA), right ventricle (RV) and left ventricle (LV). The right atria1 mass is attached to the interatrial septum (IAS). The right ventricular mass obliterates the right ventricular cavity. White arrowheads.indicate tumor masses RVA and LV cavities.
radiotracer uptake in the cardiac region on a bone imaging study, abnormal space occupying lesions in the cardiac cavity on a chest computed tomography, and cardiac ventricular masses by echocardiography. Multiple benign causes can be responsible for bone agent localization in the heart: Coxsackie B virus myocarditis [ 171, acute rheumatic carditis [18], or pericarditis [19]. Localization of bone agent in primary cardiac fibrosarcoma has not previously been reported. Intracardiac myxomas have been demonstrated by computed tomography of the chest [20,21]. Characteristic findings of myxomas with computed tomography include: (1) a lobulated heterogeneous, intracardiac mass with or without calcifications 120,211after an intravenous bolus in-
jection, and (2) frequent (but not exclusive) attachment of the mass to the atria1 septum [21]. We know of no previous reports on computed tomography of the heart which demonstrates primary cardiac tibrosarcoma. Our patient’s computed tomography with contrast media showed contrast media being absent in parts of cardiac chamber due to tumor invading or replacing the inter-ventricular septum and ventricular cavity. Invasion of ventricular cavities is probably a key to differentiation between myxoma and Iibrosarcoma. Echocardiography remains the primary method of choice when a diagnosis of cardiac myxomatous lesion is considered. Echocardiogram diagnosis of tibrosarcoma has revealed obstruction of the supe-
160
intraventricular masses or aortic outflow obstruction can differentiate fibrosarcoma from myxoma.
Acknowledgement We appreciate Dr W. O’Connor and Dr C. Pulmano for their help during the preparation of the manuscript and MS Lillian T. Owens and Mrs Aleene Miller for typing the manuscript.
Reference 1
2
3
4
5
Fig. 3. Left side of heart. Apex is replaced by fibrosarcoma (white arrowheads) and a tingerlike extension of tumor (black arrow) is seen within the left ventricular cavity.
6
1
rior vena cava and tricuspid valve; [7,8] our patient’s echocardiogram showed biventricular masses associated with aortic valve outflow obstruction. Magnetic resonance imaging (MRI), though not performed in our patient, has better tissue characteristic capabilities (22,231 and is essentially operator independent. MRI provides greater delineation of the extent and location of masses than echocardiography and may become the definitive procedure in the evaluation of cardiac masses [24,25]. In summary, this case is significant for the following reasons: (1) the diagnosis of cardiac fibrosarcoma is proven by autopsy; (2) localization of bone-imaging reagent occurs in tibrosarcoma, but does not distinguish malignant from benign conditions; and (3) echocardiographic evidence of
8
9
10
11 12
13 14
McAllister HA. Primary tumors and cysts of the heart and mediastimun. In: Harvey WP, ed. Current problems in cardiology. New York: Yearbook Medical Publishers Inc., 1979; 6-51. Goldstein S, Mahoney EB. Right ventricular tibrosarcoma causing pulmonic stenosis. Am J Cardiol 1966; 17: 570-578. Tomomatsu I, Ueba U, Akura Y, Okada S. A case with the primary hemangio-fibrosarcoma of the left atrium. Jpn Circ J 1968; 32: 881-9 Saris S, Venoulis G, Lindee J, Friedman A. Fibrosarcoma of the heart metastatic to the brain. Neurosurgery 1983; 13: 327-329. McAllister HA, Fenoglio JJ. Tumors of the cardiovascular system in Atlas of Tumor Pathology (second series, Fascile 15). Armed Forces Institute of Pathology: Washington DC, 1977; 95-98. Bloor CM, O’Rourke RA. Cardiac tumors: clinical presentation and pathologic correlations. Curr Probl Cardiol 1984; 9(6): l-48. Sethi KK, Nair M, Khanna SK. Primary tibrosarcoma of the heart presenting as obstruction at the tricuspid valve: diagnosis by cross-sectional echocardiography. Int J Cardiol 1989; 24(2): 228-230. Shrivastava S, Chopra P, Kumar AS. Fibrosarcoma of the right ventricle - a case report Int J Cardiol 1985; 9 (2): 234-238. Hanfling SM. Metastatic cancer to the heart: review of the literature and report of 127 cases. Circulation 1960; 22: 474. Fine G. Neoplasms of the pericardium and heart. In: Gould SE, ed. Pathology of the heart and blood vessels, 3rd ed. Springfield, IL: Charles C. Thomas, 1968; 875-878. Malaret GE, Ahago P. Metastatic disease of the heart. Cancer 1968; 22: 457. Davies MJ. Tumors of the heart and pericardium. In: Pomerance A, Davies MJ, eds. The Pathology of the heart. London: Blackwell Scientilic, 1975; 413. Cayley FE, Bijapur HI. Fibrosarcoma of left atrium. Br Med J 1963; I: 1134-1135. Haythorn SR, Ray WB, Wolff RA. Primary fribromysxosarcoma of heart and pulmonary Am J Pathol 1941; 17: 261-272.
15 Wall E, Vickery AL. Primary tibrosarcoma of the heart with a vertebral metastasis. Arch Path01 1947; 43: 244-252. 16 Sagerman RH, Hurley E, Bagshaw MA. Successful sterilization of a primary cardiac by supervoltage radiation therapy. AJR 1964, 92: 942-946. 17 Kao CH, Wang SJ, Yeh SH. Detection of Coxsackie B virus myocarditis on Tc-99 m Pyp myocardial imaging. Clin Nucl Med 1992; 17: 48-51. 18 Malhotra A, Radhakrishnan S, Reddy KS et al. Tc-99 m pyrophosphate myocardial scintigraphy in the diagnosis of acute rheumatic carditis. Indian J Pediatr 1989; 56: 519. 19 Wells RG, Sty JR. Extraosseous bone-tracer uptake: plasma cell granuloma. Clin Nucl Med 1986; 11: 527.
20
Norlindh T, Lilja B, Nyman U, Hellekant C. Left atria1 myxoma demonstrated with CT. AJR 1981; 137: 153-154. 21 Tsuchiya F, Kohno A, Saitoh R et al. CT findings of atrial myxoma. Radiology 1984; 151: 139-143. 22 Pflugfelder PW, Wisenberg G, Boughner DR. Detection of atria1 myxoma by magnetic resonance imaging. Am J Cardiol 1985; 55: 242-243. 23 Conces DJ, Vix VA, Klatte EC. Gated MR imaging of left atria1 myxomas. Radiology 1985; 156: 445-447. 24 Higgins CB. Overview of MR of the heart. AJR 1986; 146: 907-918. 25 Menegus MA, Greenberg, Spindola-Franc0 H, Fayemi A. Magnetic resonance imaging of suspected atria1 tumors. Am Heart J 1992; 123: 1260-1268.
157
CARD10 01683
Diagnostic imagings for primary cardiac fibrosarcoma Wei-Jen Shih, Scott McCullough and Mary Smith Department of Veterans Affairs Medical Center and University of Kentucky Medical Center, Lexington, KY 40511, USA
(Received 31 July 1992; revision accepted 8 December 1992)
Primary tumors of the heart are rare; primary cardiac fibrosarcoma is even rarer. We report a patient with primary cardiac fibrosarcoma widespread metastases presenting with pulmonary metastases initially. The cardiac lesion was identified by bone-imaging localization on bone scan, by hypodense areas in the cardiac chambers of contrast computed tomography of the chest, and by protruding masses in ventricular cavities causing aortic valve outflow-tract obstruction by echocardiogram. At autopsy, a large tumor invaded the inter-ventricular septum and both ventricular cavities of the heart (880 g in weight), and accounted for these imaging findings. While bone-agent localization in the heart does not differentiate malignant from benign conditions, computed tomography and echocardiography of the interatrial and interventricular septal, and right atria1 and biventricular cavitary involvement may differentiate tibrosarcoma from myxoma. Key words: Primary cardiac fibrosarcoma; Bone imaging agent; Computed tomography; Echocardiogram; Aortic outflow obstruction
Introduction Primary tumors of the heart are rare. Primary cardiac fibrosarcoma is even rarer, [l-5] representing only about 0.3% of cardiac tumors [l-5]. Myocardial librosarcoma is a malignant mesenchymal tumor which is primarily libroblastic in its differentiation [5,6]. It arises with equal frequency in both right and left ventricular walls [l-5]. In about 50% of tibrosarcoma patients, the tumor protrudes into a cardiac chamber, causing signiticant obstruction of a valve orifice [5,6]. Fibrosarcoma of the heart with features of obstruction of the tricuspid valve has been correctly identified by echocardiography [7,8]. Correspondence to: Dr. Wei-Jen Shih, Nuclear Medicine Service, Department of Veterans Affairs Medical Center, Lexington, KY 4051 l-1093, USA.
This report concerns a patient with bulky primary cardiac tibrosarcoma which protruded into ventricular cavities causing aortic valve outflow tract obstruction identified by echocardiogram. In addition, mass lesions of the heart were depicted by computed tomography as well as by bone scintigraphy.
Case Report A 65-year-old man with progressive cough, dyspnea, and chest pain for more than 3 weeks was admitted for workup of nodular lesions in the lungs. He had undergone two coronary artery bypass grafts in 1983. Physical examination showed expiratory wheezes and a II/VI murmur of the heart. Chest radiographs showed multiple nodular lesions. A bone scintigram 3 h after IV injection of 20 mCi Tc-99 m hydroxyl methelene diphosphon-
158
ate showed abnormally increased uptake in the posterior ribs, right acetabulum and left femoral neck; in addition, a mild increase in radioactivity was seen in the cardiac region (Fig. 1). Computed tomography of the chest showed multiple lung nodules, mediastinal lymphadenopathy and contrast media being absent in some of the chambers and parts of the cardiac chambers. Echocardiogram showed an akinetic apex of the left ventricle (LV), a myxomatous lesion on the interventricular septum, a lesion in the left ventricular outflow tract, a right atria1 mass attached to the interatrial septum and a right ventricular mass which obliterated the right ventricular cavity (Fig. 2). Bronchoscopic biopsy and endomycardial biopsies failed to identify any malignancy. An ECG showed ST elevation in the inferior leads suggesting thrombus in the apex of the left ventricle. On the 1ith hospital day, the patient developed spinal cord compression symptoms of lower extremity weakness, numbness, and urinary incontinence. A radiograph of the spine showed a T-9 vertebral compression fracture. To rule out a possibility of infection and metastasis, lumbar puncture and myelogram were attempted, but the patient refused these procedures. Steroids were then given empirically.
On the 14th hospital day the patient died. His immediate cause of death was unrelated to the massive involvement of the heart with tumor. At autopsy, intraplaque hemorrhage with luminal occlusion of the right coronary artery was the most likely antecedent to the patient’s demise. Other autopsy findings included the following: (1) greater tumor mass was in the heart. The heart was enlarged (880 g, with a normal weight of 300-350 g) and contained extensive fleshy, white, soft tumor which occupied the right ventricular free wall, obstructed the RV cavity and replaced the entire apex of the LV (Fig. 3). In addition, a finger-like projection of tumor extended from the LV free wall into the LV outflow tract to the level of the aortic valve. The tumor also invaded the epicardium surrounding the left anterior descending coronary artery, posterior descending coronary artery, and the anastamoses of the patient’s previous coronary artery bypass grafts. (2) Microscopically, primitive spindle-cell tumor infiltrated all four cardiac chambers, and was composed of elongated cells interwoven in a herring-bone pattern. Immunohistological stains demonstrated positivity with vimentin, and negative staining with HMB-45 (for melanoma), S-100, desmin, and muscle-specific actin. Electron microscopy revealed collagen production. This constellation of findings is consistent with fibrosarcoma. (3) Multiple metastases involved the lungs, mediastinal lymph nodes, liver, adrenals, small bowel and bones.
Discussion
Fig. 1. An anterior thoracic scintigraph shows a mild increase in uptake in the region corresponding to the cardiac region (arrows).
Metastatic tumors in the heart are 20-25 times more frequent than primary tumors; [9-l 21 primary cardiac tumors are rare and librosarcoma of the heart is very rare [l-5]. Patients with primary cardiac fibrosarcoma typically have the greatest tumor mass within the heart [5]. About 33% of cardiac fibrosarcomas involve the pericardium [5,6]. In 50-60%, distant metastasis involve the lung [ 131, mediastinal lymph nodes [ 141, vertebrae [15], and brain [4,16]. Our patient’s fibrosarcoma had metastasized to the epicardium, lungs, mediastinal lymph nodes, liver, adrenals, small bowel and bones. Bulky intracardiac tumor accounted for faint
Fig. 2. Echocardiogram shows mass lesions involving the interventricular septum (IVS), right atrium (RA), right ventricle (RV) and left ventricle (LV). The right atria1 mass is attached to the interatrial septum (IAS). The right ventricular mass obliterates the right ventricular cavity. White arrowheads.indicate tumor masses RVA and LV cavities.
radiotracer uptake in the cardiac region on a bone imaging study, abnormal space occupying lesions in the cardiac cavity on a chest computed tomography, and cardiac ventricular masses by echocardiography. Multiple benign causes can be responsible for bone agent localization in the heart: Coxsackie B virus myocarditis [ 171, acute rheumatic carditis [18], or pericarditis [19]. Localization of bone agent in primary cardiac fibrosarcoma has not previously been reported. Intracardiac myxomas have been demonstrated by computed tomography of the chest [20,21]. Characteristic findings of myxomas with computed tomography include: (1) a lobulated heterogeneous, intracardiac mass with or without calcifications 120,211after an intravenous bolus in-
jection, and (2) frequent (but not exclusive) attachment of the mass to the atria1 septum [21]. We know of no previous reports on computed tomography of the heart which demonstrates primary cardiac tibrosarcoma. Our patient’s computed tomography with contrast media showed contrast media being absent in parts of cardiac chamber due to tumor invading or replacing the inter-ventricular septum and ventricular cavity. Invasion of ventricular cavities is probably a key to differentiation between myxoma and Iibrosarcoma. Echocardiography remains the primary method of choice when a diagnosis of cardiac myxomatous lesion is considered. Echocardiogram diagnosis of tibrosarcoma has revealed obstruction of the supe-
160
intraventricular masses or aortic outflow obstruction can differentiate fibrosarcoma from myxoma.
Acknowledgement We appreciate Dr W. O’Connor and Dr C. Pulmano for their help during the preparation of the manuscript and MS Lillian T. Owens and Mrs Aleene Miller for typing the manuscript.
Reference 1
2
3
4
5
Fig. 3. Left side of heart. Apex is replaced by fibrosarcoma (white arrowheads) and a tingerlike extension of tumor (black arrow) is seen within the left ventricular cavity.
6
1
rior vena cava and tricuspid valve; [7,8] our patient’s echocardiogram showed biventricular masses associated with aortic valve outflow obstruction. Magnetic resonance imaging (MRI), though not performed in our patient, has better tissue characteristic capabilities (22,231 and is essentially operator independent. MRI provides greater delineation of the extent and location of masses than echocardiography and may become the definitive procedure in the evaluation of cardiac masses [24,25]. In summary, this case is significant for the following reasons: (1) the diagnosis of cardiac fibrosarcoma is proven by autopsy; (2) localization of bone-imaging reagent occurs in tibrosarcoma, but does not distinguish malignant from benign conditions; and (3) echocardiographic evidence of
8
9
10
11 12
13 14
McAllister HA. Primary tumors and cysts of the heart and mediastimun. In: Harvey WP, ed. Current problems in cardiology. New York: Yearbook Medical Publishers Inc., 1979; 6-51. Goldstein S, Mahoney EB. Right ventricular tibrosarcoma causing pulmonic stenosis. Am J Cardiol 1966; 17: 570-578. Tomomatsu I, Ueba U, Akura Y, Okada S. A case with the primary hemangio-fibrosarcoma of the left atrium. Jpn Circ J 1968; 32: 881-9 Saris S, Venoulis G, Lindee J, Friedman A. Fibrosarcoma of the heart metastatic to the brain. Neurosurgery 1983; 13: 327-329. McAllister HA, Fenoglio JJ. Tumors of the cardiovascular system in Atlas of Tumor Pathology (second series, Fascile 15). Armed Forces Institute of Pathology: Washington DC, 1977; 95-98. Bloor CM, O’Rourke RA. Cardiac tumors: clinical presentation and pathologic correlations. Curr Probl Cardiol 1984; 9(6): l-48. Sethi KK, Nair M, Khanna SK. Primary tibrosarcoma of the heart presenting as obstruction at the tricuspid valve: diagnosis by cross-sectional echocardiography. Int J Cardiol 1989; 24(2): 228-230. Shrivastava S, Chopra P, Kumar AS. Fibrosarcoma of the right ventricle - a case report Int J Cardiol 1985; 9 (2): 234-238. Hanfling SM. Metastatic cancer to the heart: review of the literature and report of 127 cases. Circulation 1960; 22: 474. Fine G. Neoplasms of the pericardium and heart. In: Gould SE, ed. Pathology of the heart and blood vessels, 3rd ed. Springfield, IL: Charles C. Thomas, 1968; 875-878. Malaret GE, Ahago P. Metastatic disease of the heart. Cancer 1968; 22: 457. Davies MJ. Tumors of the heart and pericardium. In: Pomerance A, Davies MJ, eds. The Pathology of the heart. London: Blackwell Scientilic, 1975; 413. Cayley FE, Bijapur HI. Fibrosarcoma of left atrium. Br Med J 1963; I: 1134-1135. Haythorn SR, Ray WB, Wolff RA. Primary fribromysxosarcoma of heart and pulmonary Am J Pathol 1941; 17: 261-272.
15 Wall E, Vickery AL. Primary tibrosarcoma of the heart with a vertebral metastasis. Arch Path01 1947; 43: 244-252. 16 Sagerman RH, Hurley E, Bagshaw MA. Successful sterilization of a primary cardiac by supervoltage radiation therapy. AJR 1964, 92: 942-946. 17 Kao CH, Wang SJ, Yeh SH. Detection of Coxsackie B virus myocarditis on Tc-99 m Pyp myocardial imaging. Clin Nucl Med 1992; 17: 48-51. 18 Malhotra A, Radhakrishnan S, Reddy KS et al. Tc-99 m pyrophosphate myocardial scintigraphy in the diagnosis of acute rheumatic carditis. Indian J Pediatr 1989; 56: 519. 19 Wells RG, Sty JR. Extraosseous bone-tracer uptake: plasma cell granuloma. Clin Nucl Med 1986; 11: 527.
20
Norlindh T, Lilja B, Nyman U, Hellekant C. Left atria1 myxoma demonstrated with CT. AJR 1981; 137: 153-154. 21 Tsuchiya F, Kohno A, Saitoh R et al. CT findings of atrial myxoma. Radiology 1984; 151: 139-143. 22 Pflugfelder PW, Wisenberg G, Boughner DR. Detection of atria1 myxoma by magnetic resonance imaging. Am J Cardiol 1985; 55: 242-243. 23 Conces DJ, Vix VA, Klatte EC. Gated MR imaging of left atria1 myxomas. Radiology 1985; 156: 445-447. 24 Higgins CB. Overview of MR of the heart. AJR 1986; 146: 907-918. 25 Menegus MA, Greenberg, Spindola-Franc0 H, Fayemi A. Magnetic resonance imaging of suspected atria1 tumors. Am Heart J 1992; 123: 1260-1268.