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Chin Med J (Taipei) 1997;59:136-40.
1Division of Hematology, Department of Medicine; 2Division of Cardiovascular Surgery, Department of Surgery; and 3Department of Pathology, Veterans General Hospital-Taipei and 4National Yang-Ming University, Taipei, Taiwan, R.O.C.
Primary malignant cardiac tumors are uncommon, and cardiac leiomyosarcoma is extremely rare. We reported a case of left atrial (LA) leiomyosarcoma with unusual clinical manifestations. A 28-year-old female presented with unknown cause of fever, body weight loss and anemia for two months. Echocardiography and magnetic resonance image study disclosed a 5x3x3.6 cm3 lobulated mass in the LA with invasion to its posterior wall. Histologic and immuno-histochemical studies of the resected specimen revealed a picture of leiomyosarcoma. The patient improved after surgical resection and post-operative chemotherapy. The literature was reviewed with a discussion of the clinical manifestations, diagnosis and treatment strategy of this rare tumor. Diagnosis of LA leiomyosarcoma is frequently delayed to make a very poor prognosis. Postoperative chemotherapy should be considered because of highly possible incomplete resection. However, an optimal treatment regimen remains unknown.
[Chin Med J (Taipei) 1997;59:136-40.]
Keywords: fever of unknown origin, heart, left atrium, leiomyosarcoma
Received: June 12, 1996.
Accepted: October 19, 1996.
Address reprint requests to: Hui-Chi Hsu, M.D., Division of Hematology, Department of Medicine, Veterans General Hospital-Taipei, No. 201, Shih-Pai Road, Taipei, Taiwan, R.O.C.
Primary cardiac tumors are rare, and the majority of them are benign and curable. Malignant tumors account for only 10% of all the cases, and most of them are vascular in origin; angiosarcoma is one of the examples [1]. Leiomyosarcoma is even rare. The patients affected generally present with nonspecific symptoms, and the diagnosis is usually made only after death. Here a case of primary leiomyosarcoma of the left atrium (LA) is reported, with an unusual manifestation of fever of unknown origin (FUO).
A 28-year-old woman was admitted to the hospital because of FUO for 2 months and body weight loss. The patient had been in excellent healthy condition until 7 months before when she began to have an intermittent high fever. She was admitted to another hospital where physical examination as well as laboratory examinations, including blood and urine culture, chest radiographic study and echocardiography, were all normal. She was then transferred to our hospital. Physical examination on admission revealed a chronically ill appearing woman with anemic conjunctiva and clubbing fingers. There was no lymphadenopathy or hepatosplenomegaly. Her body temperature was 40OC; the pulse rate 108 and respiration rate was 32 per minute. Hematological studies showed hemoglobin 6.4 mmol/L; leukocytes 18x109/L; platelet 825x109/L; serum ferritin 565 micron g/L Blood biochemical analysis showed alanine aminotransferase 102U/L; aspartate aminotransferase 114 U/L; alkaline phosphatase 249 U/L; gamma-glutamyl transpeptidase 105 U/L; lactate dehydrogenase 250 U/L. Hepatitis B surface antigen and antibody to hepatitis C virus were both negative. She received bone marrow and liver biopsy. The specimens of both tissues showed reactive plasmacytosis and non-specific hepatitis respectively, without evidence of infection or malignancy. Serological studies showed C-reactive protein 25.5 mg/dl, and the absence of antinuclear antibody. Serial cultures of blood, sputum and urine showed no evidence of bacterial or fungal infection. The woman was treated empirically with broad-spectrum antibiotics and anti-tuberculosis medication, but the fever persisted without any clinical improvement. Two weeks after admission, a grade II/VI diastolic murmur was found over apex. Transthoracic and transesophageal echocardiography disclosed a homogenous tumor mass originating from the posterior portion of the LA (Figure 1). Ultrafast computed tomography (CT) and magnetic resonance image (MRI) further disclosed a tumor measuring 5x3x3.6 cm3 in size and invading the posterior wall of left atrium (Figure 2), suggesting a malignant origin. No other tumor or lymphadenopathy was found in the chest or abdominal CT.
The patient underwent thoracotomy, cardiopulmonary bypass and cardioplegic arrest for left atrial tumor resection. A cauliflower mass located on the outlets of the bilateral inferior pulmonary veins was found to extend to the left atrial appendage, invade the mitral valve annulus and cause partial obstruction of the bilateral superior and inferior pulmonary veins. Histologic examination of the resected specimen showed a picture of sarcoma with interlacing bundles of neoplastic spindle cells (Figure 3). The tumor cells were poorly differentiated with bizarre nuclei and frequent mitotic figures. The lesion also invaded into the superficial myocardium and extended to the mitral valve. Focal necrosis and erosion with neutrophil and macrophage infiltration were also found. The immunohistochemical studies showed the tumor cells positively stained by vimentin, muscle-specific actin and focally stained by desmin, while negatively stained by myoglobin. The result of immunohistochemical studies was compatible with leiomyosarcoma.
The post-operative recovery was uneventful. The patient received chemotherapy with adriamycin and dacarbazine. Fever and anemia disappeared. She had kept in stable condition for five months after operation till this report.
Primary tumors of the heart are rare and have most often been diagnosed at postmortem. A Medline search shows only 11 such cases that have been diagnosed antemortem and reported in the English literature [2-11] (Table 1). These cases were female predominant, with a median age of 47 years (18- 62 years). Clinical presentations were usually non-specific: cough, chest pain and hemoptysis, causing an average of 4.5 months delay in diagnosis. FUO has also been reported as rare presentation in the leiomyosarcoma of other organs such as gastrointestinal tract, pharynx and uterus than the heart [12-14].
Non-invasive two-dimensional transthoracic echocardiography has become a well-established screening tool for intracardiac lesions. However, its diagnostic accuracy has been estimated to be only 48% [15]. It can be further improved by applying transesophageal echocardiography, which provides better visualization of the posterior portion of the heart [15,16]. Misdiagnosis of such polypoid atrial sarcoma, or more frequently myxoma, is common. In this case, the malignant tumor had been diagnosed preoperatively by MRI to disclose tumor invasion into the posterior wall of LA. MRI is superior to echocardiography for evaluating intramural tumors and their nature; thus, this procedure should be included in the diagnostic work-up of intracardiac tumors [17].
The treatment of cardiac leiomyosarcoma is primarily surgical but can only serve as palliative therapy because of the highly aggressive and locally invasive nature of the tumor. Previous report of operative findings in nine patients showed invasion into the LA wall in all cases; invasion of the pulmonary veins in eight; mitral valves in four; left ventricle in two and mediastinum in one patient [2-11]. Debulking procedure by removing obstructive pulmonary venous extensions offers rapid relief of pulmonary venous hypertension and associated dyspnea [1]. However, prognosis is dismal because the tumor is usually inadequately resected. Most patients with primary LA leiomyosarcoma died of local relapse with or without distant metastasis and had a median survival of only six months (0-23 months; Table 1). There is controversy regarding adjuvant therapy. As reported by Antunes et al, chemotherapy considerably prolonged survival [4]; however, this has been questioned by others [7]. Doxorubicin, along with dacarbazine, has been suggested as two possible useful chemotherapeutic agents since they have proved of some benefit in treating other soft tissue sarcomas [18]. However, an optimal management of leiomyosarcoma originating in the left atrium still remains unclear till the present time.
Copyright: 1997, Chinese Medical Association (Taipei)