Primary Leiomyosarcoma of the Left Atrium

Abstract

rimary malignant tumors of the heart are extremely rare, and leiomyosarcoma is the rarest among these tumors. The prognosis of leiomyosarcoma is reported to be very poor even if surgical resection, with or without adjuvant chemotherapy and radiotherapy, is performed. Here we present our case of primary leiomyosarcoma of the left atrium and discuss the diagnosis, treatment and prognosis by reviewing the literature. Case ReportA 69-year-old woman had intravenous fluid administered at a clinic due to general fatigue, but as she subsequently developed dyspnea with cyanosis and respiratory arrest, she was transferred to hospital with cardiopulmonary resuscitation and was admitted to the cardiac care unit after intubation. Chest roentgenography demonstrated severe lung congestion and mild cardiomegaly. Transesophageal echocardiography revealed what was suspected to be a giant myxomatous tumor in the left atrium, which extended to the orifice of the mitral valve and obstructed the pulmonary veins (Fig 1); however, no tumor stalk was observed on the atrial septum or left atrial wall. A hemodynamic study demonstrated that the pulmonary artery pressure and mean pulmonary capillary wedge pressure were 42/32 and 30 mmHg, respectively, and the cardiac index was 3.6 L min -1 m -2 .The patient underwent surgery under standard cardiopulmonary bypass via median sternotomy. After administration of antegrade cold crystalloid cardioplegia, the left atrium was incised longitudinally. The tumor occupied most of the left atrial cavity and adhered to the wall, so a right atriotomy with atrial septal incision was also performed to expose and excise the tumor. The tumor, which was solid and partially calcified with thrombus, was carefully dissected and resected. An area of the tumor extended into the pulmonary veins and obstructed the inflow of the left atrium and this was excised and removed as much as possible, but no attempt was made to excise the atrial wall or pulmonary veins, because it was unclear whether the tumor arose from the left atrium or the pulmonary veins. The mitral valve was normal and not invaded by the tumor. After repairing the left and right atria, the patient was weaned from the cardiopulmonary bypass without difficulty.The excised tumor was 5×6 cm in dimension, 95 g in weight, and grayish in color with thrombotic nodules on its surface. Histopathological examination demonstrated a spindle cell tumor, with a high rate of mitosis indicating Jpn Circ J 1999; 63: 414 -415 (Received December 4, 1998; revised manuscript received January 25, 1999; accepted February 3, 1999 A 69-year-old woman with symptoms of congestive heart failure had a left atrial leiomyosarcoma, an extremely rare cardiac tumor, which obstructed the mitral valve and pulmonary veins. Surgical resection was performed, but no other adjuvant therapy was administered because the patient refused it. Recurrence of the tumor occurred soon after surgery and the patient died 81 days postoperatively. (Jpn Circ J 1999; 63: 414 -415)

Primary Left Atrial Leiomyosarcoma: Literature Review and Lessons of a Case

“…As a result, in most reported cases, as in our case, preoperative diagnosis has been impossible. 6 In this case, the diagnosis of left atrial myxoma was confi rmed by histopathological examination. Histopathological misinterpretation of the tumor is common because the morphological differentiation of cardiac myxomas and sarcomas may sometimes be diffi cult.…”

“…4,13 In addition, extensive resection of the left atrium and replacement with an allograft and simultaneous pulmonectomy has also been reported, without a reliable result. 6,18 In our case, primary tumor resection and removal of the fi rst relapse could be regarded as non-radical procedures. As to the second relapse, we had many reasons to consider this procedure as completely radical.…”

“…3,10 The echocardiographic distinction between leiomyosarcoma and myxoma is also diffi cult. 6 The affi nity of myxoma with the midportion of the left atrial septum in the fossa ovalis is not a suffi cient differentiating feature. 3 Pericardial effusion may be prevented by dense pericardial adhesions in tumor relapses.…”

“…17 In spite of the fact that radical surgical resection of the tumor is the only chance of prolonging the patient's life, the results of surgical treatment are palliative in most cases because of the inevitable tumor relapses or metastases. 1,3,6,9 The average survival without operation is 6 to 12 months. [1][2] Surgery extends survival to 24 months.…”

“…Radiotherapy may help to control local tumor growth, however, leiomyosarcoma is a malignant tumor of low radiosensitivity. 6 There is a risk of the development of radiation myocarditis and pericarditis with high doses of radiation. 6 The benefi ts of postoperative chemotherapy are also unknown.…”