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.