Case report
A 17-year old boy presented with chest pain and off & on palpitations. Echocardiography revealed a large cyst (7 x 6.8 x 7 cm) around posteroinferior part of mediastinum and extending laterally. Magnetic resonance imaging (MRI) revealed well defined cystic mass lesion in the posterior, inferior and lateral aspect of left cardiac border appearing hyperintense on STIR sequences and hypotense on T1 sequence. (Figure 1)
Therefore, pericardial cyst removal via small thoracotomy was planned after taking infirmed consent. Thoracotomy was done but pericardium was found adherent posteriorly and superiorly and cyst appeared to be epicardial in origin. Therefore we planned to proceed via median sternotomy. Cyst was adhered to the pericardium and base was formed by visceral pericardium and myocardium of inferior wall of left ventricle. The cyst was most tightly attached to the left ventricle inferiorly. Thus, it was thought to have originated from the postero-inferior portion of LV. Cyst was found to be pushing the ventricles anteriorly. As the dissection of the mass was difficult and because of adhesions and close proximity to posterior descending artery we proceed with cardiopulmonary support.
Cyst wall was thick and vascular with feeder vessels over the surface. (Figure 2a) It was completely dissected and excised from its attachment. Inspection of the floor showed certain erosion of myocardial tissue, and the thickness of ventricular wall was attenuated. The cyst edges were trimmed, and multiple bleeding points along the cut edges were controlled with suture ligatures. The edges were then plicated over the attenuated ventricular wall with sutures to reinforce it. (Figure 2b)
Histopathology revealed single layer of mesothelial cells. In addition to blood and lymphatic vessels, smooth muscle cells, lymphocyte infiltration, and fibrosis were observed (Figure 3).
The follow-up 2-dimensional echocardiography after 6 months did not show any abnormalities.