Caseous calcification of the mitral annulus mimicking benign cardiac tumour of the mitral valve.

Caseous calcification of the mitral annulus (CCMA) is a rare subtype of mitral annular calcification. It usually appears as a large, round, mass-like calcification with an echolucent core, which may be misdiagnosed as an intracardiac mass, cyst, thrombus or abscess of the mitral valve. We present a case report of CCMA that was misdiagnosed by echocardiography as a benign tumour due to its atypical imaging. The mitral valve mass was resected and it was pathologically confirmed to be a myxoid change with calcification. Echocardiography is the preferred initial diagnostic tool. Myocardial contrast echocardiography (MCE) is used to evaluate the vascularity of intracardiac masses or mass-like lesions, but neither echocardiography nor MCE is reliable for identifying atypical lesions. Cardiac computed tomography is helpful in establishing a diagnosis by showing dense calcifications, while cardiac magnetic resonance imaging is used primarily as a credible tool. We therefore recommend that a diagnosis should be made based on various imaging modalities, if necessary, and operators should be skilled to avoid misdiagnosis.