Mitral annular calcification: Can CMR be useful in identifying caseous necrosis?

Mitral annular calcification (MAC) can resemble an intracardiac mass and it is defined as a chronic degeneration of the mitral annulus. Often reported is caseous mitral annulus calcification (CMAC), a periannular, extensive calcification resembling a tumor. We report the case of a 68-year-old woman who had been hospitalized for palpitations and dyspnea. The transthoracic and transesophageal echocardiography revealed a non-homogeneous, slightly mobile, round mass, attached to the ventricular side of posterior mitral leaflet, with central echo lucent area and without acoustic shadowing. Therefore, a cardiac magnetic resonance (CMR) was performed; delayed enhancement sequences showed a non-enhanced central core surrounded by a hyperenhanced rim (fibrous cap). To confirm the diagnosis, a multidetector computed tomography (MDCT) was performed; the MDCT showed a hyperdense mass with a hypodense center and a calcified peripheral rim. The central content had heterogeneous fluid density without significant contrast enhancement. The MDCT findings were considered highly suggestive of CMAC. CMR may be useful for the identification and definition of pericardial and myocardial masses and CMAC.