Discussion
We present a rare case of cardiac leiomyosarcoma in a young lady who treated surgically, followed by adjuvant chemotherapy. The patient is still alive without metastasis after 9 months of follow-up.
There are few reports of limited cases in the literature about primary cardiac leiomyosarcoma. Wang et al. reviewed all the literature and identified 79 instances derived from 72 unique reports with primary cardiac leiomyosarcoma (4). In this study, the median age at diagnosis was 48 with a female predominance, and the symptom of obstruction was the most common complaint at diagnosis. The recurrence-free survival and the 5-year overall survival rates were 14.7% and 25.4%, respectively. They showed that overall survival was affected by age, surgery, and adjunct chemotherapy or radiotherapy in this study. In our case, the patient had mild dyspnea and a history of treatment with a respiratory infection. The diagnosis was suspected on the findings of a CT performed for pneumonia.
Echocardiography is usually the initial imaging modality for cardiac masses. It may show its extent, location, and hemodynamic effects (Figure 1). CT scan and cardiac MRI supply additional instructions about morphology, location, and extent of the mass (Figure 2) (6). CT scan is helpful to evaluate extracardiac extent or metastasis, and cardiac MRI has been shown to differentiate the tumor from a thrombus by contrast enhancement (3). Moreover, MRI is more useful to assess myocardial involvement. For the differential diagnosis of a mass lesion, PET CT helps differentiate the results of CT and MRI (7). In our case, we used PET CT and MRI for the definitive diagnosis of the cardiac tumor and for the follow-up.
The most common cardiac chamber of cardiac leiomyosarcomas in the left atrium (51%), like our case. A biopsy is the gold standard for histological confirmation, but this step can sometimes be overcome, especially in cardiac masses, and then diagnosed by histopathological examination of the resected mass (6).
The best treatment strategy is not certain; but, early diagnosis and adequate surgical resection remain the mainstay for the treatment of this tumor in the literature (3). Adjuvant radiotherapy and chemotherapy have been shown to prolong survival and improve disease control in some cases (7). Frozen section guided excision border of 1cm for all left atrial tumors was suggested by Marin and colleagues for better survival (7). Adequate excision of a pulmonary vein tumor may require lung resection ranging from lobectomy to pneumonectomy (3). In our case, the left atrial tumor was extending to the branches of the pulmonary veins, so the right inferior lobectomy with right inferior pulmonary vein excision was performed to reach the clean surgical margin. Adjuvant radiotherapy and chemotherapy was given to our patient by multidisciplinary staff decision.
The conventional median sternotomy approach is widely used in cardiac tumors operations. This approach has great exposure; on the other hand, it also coexists with some troubles, such as poor cosmetic effect, sternal dehiscence and risk of postoperative mediastinitis (8). Since Ko et al. reported the cardiac myxoma excision via the right anterolateral mini-thoracotomy approach two decades ago (9), minimally invasive approaches have been progressively performed to the treatment of cardiac tumors. However, because of the rareness of primary cardiac tumors, there are only limited reports in the literature. In addition, there are some concerns about incomplete tumor resection with minimally invasive surgery due to insufficient minimally invasive experience, and the clinical benefit of this approach is still controversial, especially for cardiac masses. Luo et al. conducted a study on 50 patients with primary benign cardiac tumors who underwent either conventional or minimally invasive surgery from 2008 to 2018 (10). In this study, there was no significant difference in aortic cross-clamp time and cardiopulmonary bypass time between the two groups and the duration of postoperative intubation time, intensive care unit stay, and hospital stay were shorter in the minimally invasive group, but the differences were not statistically significant.
The necessity of lung resection is high for this type of tumor, and it may difficult to perform from median sternotomy. Additional right thoracotomy may be needed. We suggest that the right submammarian thoracotomy approach is feasible and effective for both cardiac tumor resection and right lower lobectomy.
The recurrence rate is high in cardiac leiomyosarcomas despite optimal surgical resection of the primary tumor. According to the literature of cardiac leiomyosarcomas, the mean survival time of patients who underwent surgery and chemotherapy was about 12 months (2,3,4).
In our case above, she is still alive, and there is no evidence of local or distant recurrence or metastasis after a follow-up of 12 months.