Fibrous cyst of the chordae tendineae of the mitral valve: echocardiographic appearance and literature review.

Fibrous cyst of the chordae tendineae of the mitral valve (MV) is defined as a fibrous cyst arising from the chordae tendineae of the MV. It is extremely rare and its etiology is not clear. We present a case of a cystic structure within the left ventricle. This structure is connected to the anterior MV leaflet and the posterior chordae tendineae. It moves freely, resulting in stenosis of inflow tract and outflow tract of the left ventricle. Intraoperative assessment and histopathologic examination revealed it as a fibrous cyst. Its echocardiographic appearance is unique and it must be resected immediately.