Primary cardiac chondrosarcoma

Primary Cardiac Chondrosarcoma SHU-HANG NG, MD,* SHEUNG-FAT KO, MD,* TSAI-SHEN YANG, MD,t HO-FAI WONG, MD,* YUNG-LIANG WAN, MD,* YET-SEN HO, MD::I: A case of primary cardiac chondrosarcoma in a 41-year-old woman who presented with cardiac tamponade and cardiac intracavitary obstruction is described. The tumor originated from the right atrium and invaded the adjacent right ventricular wall and interatrial septum, Primary cardiac chondrosarcoma is extremely rare, and its clinical, computed tomographic, echocardiographic, and magnetic resonance imaging findings are described. (Am J Emerg Med 1996;14:285-287. Copyright © 1996 by W.B, Saunders Company) Primary sarcomas of the heart are uncommon and constitute less than 25% o f primary cardiac tumors. 1 Cardiac chondrosarcomas are exceedingly rare. In 1970, McConnell 2 reviewed the literature and found only six reported cases of primary cardiac tumors with bony or cartilaginous elements. Two additional cases of primary cardiac chondrosarcoma were reported by Winer et al3 and Bashi et al4 in 1977 and 1989, respectively. To our knowledge, no computed tomography (CT) or magnetic resonance imaging (MRI) finding has been reported hitherto. Herein, we report a case of primary chondrosarcoma of the heart that was evaluated with echocardiography, CT, and MRI.

CASE REPORT A 41-year-old healthy woman suddenly experienced shortness of breath, malaise, and back pain for 1 day. She was sent to our emergency department (ED) because of cyanosis and disturbance of consciousness lasting several hours. On examination, the patient was confused and her blood pressure was 75/30 mm Hg. Her lips were cyanotic. Her neck was supple with engorged veins. The breathing sound was coarse with wheezing. Her heart beat was irregular, and the heart sound was distal. Extremities were cold and cyanotic, and the pulses were weak. Electrocardiogram showed sinus tachycardia. The central venous pressure (CVP) was 30 cm H20. Chest radiography showed an enlarged cardiopericardial silhouette and bilateral pleural effusion. CT of the chest was performed to diagnose or exclude aortic dissection. A large filling defect in the fight atrium with obliteration of adjacent epicardial fat and a

From the *Department of Diagnostic Radiology, tDepartment of Internal Medicine, and :l:Department of Pathology, Chang Gung Medical College and Chang Gung Memorial Hospital,Taipei,Taiwan. Manuscript receivedMarch 21, 1995, acceptedApdl 15, 1995. Address reprint requests to Dr Ng, Department of Diagnostic Radiology, Chang Gung Memorial Hospital, 5 Fu-Shing Street, Kwei Shan, Tao Yuan, Taiwan, R.O.C. Key Words: Heart, neoplasms, chondrosarcoma, magnetic resonance imaging. Copyright © 1996 by W.B. Saunders Company 0735-6757/96/1403-001455.00/0

high-density pericardial effusion were seen, and no evidence of aortic dissection was detected (Figure 1). Thereafter, the patient underwent emergency surgery. During thoracotomy, 250 mL bloody pericardial effusion leading to cardiac tamponade and a large tumor occupying the fight atrium were noted. After subxyphoid pericardial drainage, the blood pressure of the patient returned to normal but the CVP was still high (about 30 cm H20). A transesophageal two-dimensional echocardiogram showed an echogenic mass in the right atrium wall and clearance of the pericardial effusion (Figure 2). A second operation for releasing the cardiac inflow obstruction by the cardiac tumor was performed. At open heart surgery under extracorporeal circulation, a large tumor in the fight atrium with involvement of the interartial septum and right ventricle was found. Because of the diffuse attachment of the tumor on the fight cardiac wall, only a subtotal resection of the right atrial tumor could be done. Histological examination of the resected specimen showed a high-grade chondrosarcoma (Figure 3). Detailed examination of our patient (including bone scan and radiographic survey) did not disclose any other tumor in the body. The patient was subjected to MRI to evaluate the residual heart tumor. MRI with cardiac gating and respiratory compensation on 1.5 Tesla scanner (Signa, GE Medical Systems, Milwaukee, WI) delineated a lobulated mass attached to the lateral wall of the right atrium and extending into the interartial septum, right ventricle, and adjacent pericardial space. The mass was of intermediate signal intensity on Tl-weighted images and heterogeneous high signal intensity on T2-weighted images. Postgadolinum Tl-weighted imaging demonstrated heterogeneous enhancement of the mass, with greater enhancement at the periphery and septa of the lesions (Figure 4). The patient refused radiotherapy and was discharged in a stable condition. She subsequently died of respiratory failure caused by bilateral pulmonary metastases and pleural effusion 8 months later.

DISCUSSION A primary tumor of the heart is rare, with an autopsy incidence ranging from 0.0017% to 0.03%. 5,6 About three quarters are histologically benign with myxomas accounting for up to half of the cases. Malignant tumors are predominantly sarcomas, most commonly angiosarcoma and rhabdomyosarcoma. 1,7 Primary cardiac chondrosarcomas are extremely rare, and to our knowledge, only 8 cases have been recorded in the English-language literature. 2-4 The patients were usually women with an average age of 46 years. Cardiac sarcomas frequently occur in the fight side of the heart, particularly the right atrium. Although these malignant tumors originate from the endocardium and pericardium more often than from the myocardium, they usually infiltrate all layers of the heart, invade adjacent mediastinal 285

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FIGURE 1. Contrast CT shows pericardial effusion and a soft tissue mass in the right atrium with obliteration of adjacent epicardial fat. CVP is in place (arrow). structures, and widely metastaize. Systemic metastases are present in 80% of patients when they are first seen. The lungs and mediastinal lymph nodes are especially' susceptible to metastatic deposits. 7 The clinical presentations include intracavitary obstruction, cardiac tamponade, peripheral embolism, congestive heart failure, and various constitutional symptoms. The prognosis is generally poor, and survival is measured in weeks or months. Because cardiac sarcomas are seldom localized by the time they are identified, complete resection is rarely possible. Nevertheless, surgery is recommended not only to obtain a tissue diagnosis but also to relieve the tumor compression, because partial or complete relief of symptoms may significantly improve duration and quality of survival. 8,9 In our patient, the clinical presentation showed cardiac tamponade and intracavitary obstruction with resultant hemodynamic shock. The symptoms were relieved by surgery for about 8 months, after which the patient succumbed from lung metastases.

FIGURE 2. Transesophageal echocardiogram shows an echogenic mass in the right atrium.

FIGURE 3. Histology shows sheets of anaplastic cells with cartilagenous differentiation containing malignant chondrocystes (Hematoxylin and eosin; original magnification, X200).

Echocardiography remains the initial study of choice for the evaluation of cardiac masses, while CT and MRI can provide further information. In our case, echocardiography showed that the cardiac chondrosarcoma was of strong echogenicity, similar to the sonographic pattern previously reported. 3 CTdepicted a large soft tissue mass occupying the right atrium without any tumoral calcification, although tumoral calcification has been described as a feature o f chondrosarcoma and was demonstrated fluoroscopically in a previously reported case. 4 The mass obliterated the adjacent epicardial fat pad, suggesting that the lesion transgressed the right atrial wall to extend into the pericardial space. CT also detected a high-density pericardial effusion compatible with hemopericardium, Recognition of these CT findings is not only important to identify the causes of the patient's symptoms but also helpful in suggesting the possibility of cardiac malignancy. Furthermore, CT denoted the presence of pleural effusion as well as the absence of lung metastasis and mediastinal lymphadenopathy. MIni showed that the residual chondrosarcoma was of slightly heterogeneous intermediate signal intensity on T1- and increased signal intensity on the T2-weighted images. Following intravenous administration of gadopentetate dimeglumine, the mass exhibited definite heterogeneous enhancement. MRI better defined the extent of the tumor. The extension of the right atrial tumor to the interatrial septum and right ventricular wall, as well as beyond the myocardium into the pericardial space with disruption of the pericardium, was clearly delineated. Although the MRI signal changes were not specific, the demonstration of such extra-chambered extension could assist in recognizing the malignant nature of the mass. As far as we know, the present case represents the first case of primary cardiac chondrosarcoma imaged by CT and MRI. Although rare, chondrosarcoma should be included in the differential diagnosis of heart masses with similar clinical presentations and imaging features.

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FIGURE 4. MRI of the heart after partial removal of the fight atrial chondrosarcoma. (A) Axial Tl-weighted image shows a lobulated mass of heterogeneous intermediate signal intensity in the fight atrium. (B) Proton image and (C) T2-weighted image show the mass heterogeneously hyperintense to the myocardium, with involvement of the right ventricle and interatrial septum. In addition, disruption of the thin pericardial low intensity band in the area of the tumor is noted. (D) Postgadolinum Tl-weighted image with fat suppression technique shows heterogeneous enhancement of the mass.

REFERENCES 1. Sanoudos G, Reed GE: Primary cardiac sarcoma. J Thorac Cardiovasc Surg 1972;63:482-485 2. McConnell TH: Bony and cartilaginous tumors of the heart and great vessels. Cancer 1970;25:611-617 3. Winer HE, Kronzon I, FoxA, et al: Primary cardiac chondrosarcoma: Clinical and echocardiographic manifestations: A case report. J Thorac Cardiovasc Surg 1977;74:567-570 4. Bashi VV, Walter A, John A: Primary chondrosarcoma of heart. Ind J Chest Dis Allied Sci 1989;31:203-206

5. Straus R, Merliss R: Primary tumors of the heart. Arch Pathol 1945;39:74-78 6. Lancaster LD, Ewv GA: Cardiac consequences of malignancy and their treatment. Adv Intern Med 1984;30:275-293 7. Silverman NA: Primary cardiac tumor. Ann Surgery 1980;191: 127-138 8. Dein JR, Frist WH, Stinson EB, et al: Primary cardiac neoplasm. Early and late results of surgical treatment in 42 patients. J Thorac Cardiovasc Surg 1987;93:502-511 9. Murphy MC, Sweeney MS, Putnaum JB Jr, et ah Surgical treatment of cardiac tumors: A 25-year experience. Ann Thorac Surg 1990;49:612-617