Lymphangioma of the heart as a rare tumor: A case report

Highlights • Lymphangioma is a rare cardiac tumor.• Lymphangiomas are benign in nature.• Diagnosis based on imaging techniques is difficult.• Surgery may be needed for definitive diagnosis and treatment.


Introduction
Tumors of the heart are uncommon and lymphangiomas are among the rarest of this group, with very few cases reported in the literature [1].
These tumors consist of a benign slow-flow vascular malformation containing lymphatic elements, forming a mass [2]. The head and neck are the most frequent locations for this tumors and they are more frequently observed during childhood. However, they may appear, or be detected, later in life as well [3].
Although cardiac lymphangioma is of benign nature, it should be considered in the differential diagnosis of vascularized soft tissue masses together with other more aggressive pathologies, such as angiossarcoma, lymphoma and metastatic disease. Usually, the diagnostic approach is surgical, given the increased risk of bleeding related to percutaneous biopsy [4]. Diagnosis based on imaging techniques is difficult, though the most useful method seems to be the magnetic resonance imaging (MRI) by elucidating the slow-flow components present in vascular malformations [5].
In line with the SCARE criteria, we report a case of a man diagnosed incidentally with a cardiac mass and our surgical approach [6].

Case report
A 67-year-old male patient with no significant medical history presented to our institution to check a mediastinal enlargement incidentally found on routine chest X-ray. Echocardiographic examination revealed a solid mass surrounding the right cardiac chambers, and computed tomography of the chest confirmed the presence of a right lateralized 12 × 4 cm soft tissue mass beginning in the antero-superior pericardium recess down to the right atrium and right ventricle (Fig. 1). The mass did not contain calcification and it appeared adjacent with the right atrium. There was no pericardial effusion.
The subsequent techniques included a completely unremarkable coronariography with no signs of any neovascularization to the mass. The magnetic resonance imaging (MRI) confirmed the presence of an intrapericardial mass, with hypersignal in T2, localized in the anterior and superior pericardial recess, with inferior extension along the interatrial groove, and free wall of the right atrium and ventricle, surrounding the right coronary artery, but with apparent cleavage plane (Fig. 2).
Median sternotomy approach was used to access the mass. The mass was completely adherent to the right atrium, right ventricle, and right coronary artery (Fig. 3). Due to this adherence, and the lack of a pathologic diagnosis, we ruled it unsafe to attempt a total resection of the mass, and instead performed a partial resection. The macroscopic examination of the cut surface revealed a large cystic space, with smaller spaces dispersed in a fibrotic wall (Fig. 4).   The patient had a normal post operative recovery and was discharged four days after the surgery. The patient was clinically well after one month.
The pathology specimen showed a mass containing lymphoid tissue, and the immunohistochemistry stains were consistent with a cardic lymphangioma.

Discussion
In this case, we have described a case of a pericardial mass for which the MRI suggested a cleavage plane between the myocardium and the tumor, which we were not able to confirm at surgery. Because of this, rather than a total resection with a very high operative risk, a biopsy was preferred due to the possibility of the tumor be benign.
The pathology specimen showed a benign tumor and at 1-month follow-up, the patient was clinically well. He was referred to the cardiologist for regular follow-up with serial echocardiograms to monitor the behavior of the mass.

Conclusion
Lymphangioma is a very rare vascular malformation, hence there are very few cases reported in the literature (Table 1). Consequently, no consistent guidelines for treatment and follow-up are available.
In our case, as the patient was entirely asymptomatic and complete resection would have been a very complex and dangerous procedure, we opted for the surgical biopsy. Even in cases when the MRI does not show a visible cleavage plane, the safest, and more suitable option, is always a surgical biopsy because these masses tend to bleed easily. Therefore, a differential diagnosis with consideration of other malignant diseases is necessary, since there is no specific investigation to identify this particular tumor.

Conflicts of interest
The authors don't have any financial and personal relationships that could influence their work.

Funding source
Nothing to declare.

Ethical approval
This is a case report. Informed consent was obtained from the patient and submitted to ethics committee of CHLN -Hospital Santa Maria according to protocol.

Consent
Written consent was obtained from the patient for publication of this case and accompanying images. A copy of the written consent is available for review by the editor-in-chief of this journal on request.

Authors contribution
Ricardo Ferreira, Study conception and design, data collection, revision of the paper. Nadia Junqueira, Data collection and writing the paper. Joã, Writing and revision. Angelo Nobre, Revision and supervision.

Registration of research studies
Not Applicable.

Ethical Approval and consent participate
Manuscript was approved by the Ethics Committee of Hospital de Santa Maria and Centro Académico de Medicina de Lisboa. The reference number is 365/18.
A copy of the ethical approval is available for review by the editor-in-chief of this journal on request.

Provenance and peer review
Not commissioned, externally peer reviewed.