Serial Cardiac Magnetic Resonance Imaging of a Rapidly Progressing Liquefaction Necrosis of Mitral Annulus Calcification Associated With Embolic Stroke
M itral annulus calcification (MAC) is a common finding in the elderly. A rare manifestation of MAC is liquefaction necrosis that can be mistaken for a tumor or an abscess. Because its course is most often benign, a correct diagnosis is imperative to avoid unnecessary workup or treatment. Case A 76-year-old woman with history of hypertension and dyslipidemia presented with chest pain and elevated cardiac enzymes. A coronary angiogram revealed no significant coronary artery disease.
... sease. Echocardiogram ( Figure 1 ) revealed a large, solid mass within the atrioventricular groove and the lateral wall of the left ventricle. There was moderate calcification of the mitral valve annulus. Computed tomography scan of the chest ( Figure 2 ) revealed a soft tissue density inseparable from the region of the mitral valve and the left ventricular wall. Cardiac magnetic resonance (CMR) showed a large mass involving the basal lateral wall near the atrioventricular groove, extending into the left atrium ( Figure 3A and 3B). The mass was slightly hyperintense on T1 ( Figure 4 ) and hypointense on T2 imaging ( Figure 5 ). The mass was homogenous on delayed enhancement with a bright ring (Figure 6 ), the characteristics were not changed with fat saturation, and it was avascular by perfusion ( Figure 7) . The patient was discharged from the hospital with a scheduled outpatient workup to continue. The patient returned 2 weeks later, however, with an acute stroke in Ͼ1 arterial distribution, and workup for an embolic source commenced. A CMR ( Figure 3C and 3D) revealed no left ventricular thrombus; the mass increased in size and changed in consistency, appearing semisolid. The patient underwent a left thoracotomy for a biopsy, which revealed a thick whitish fluid (Figure 8 ) thought to be Figure 1. Echocardiography images before and after biopsy. A, 4-chamber view performed on presentation, reveals a soft tissue mass involving the atrio-ventricular groove, the left atrium, and left ventricle. There is moderate calcification of the mitral valve. B, 4-chamber view performed after biopsy. The mass has decreased in size and appears cystic. White arrows indicate the mass.