Corresponding author:
Jama Jahanyar, MD PhD FACS
Cliniques Universitaires Saint-Luc
Avenue Hippocrate 10, 1200 Brussels, Belgium
+3227646113, fax: +3227648960
jjahanyar@gmail.com
Word Count: 500
Caseous calcifications of the mitral annulus(CCMA) have been reported
with a 2.7% prevalence in a necropsy-series1.
However, the exact frequency is unknown, and it’s rare in our own
clinical experience. An echocardiographic-study estimated the prevalence
in the general population as 0.06%–0.07%2.
These intra-cardiac tumors are often incidental findings on
Echocardiography(Figure1) in older-aged patients(e.g. diabetic-,
hypertensive-, renal-failure patients), and can be mistaken for an
abscess in the setting of questionable endocarditis. They are
encapsulated, and rupture of its capsule can lead to chimney-like
protrusions of a thick toothpaste-like material, with potential for
severe embolic sequalae. The surgical approach entails Incision &
Drainage of the lesion(Figure1), with either mitral valve repair or
replacement. Our general approach is through the left atrium(Video1).
In this case the pathologic evaluation demonstrated calcifications with
foci of lymphoplasmocytic infiltrates, with a mix of hemosiderin-laden
neutrophils and macrophages. There were focal non-necrotic
cardiomyocytes identified in the specimen. The microbiology evaluation
was negative for an infectious process. Clinically, the mass did not
cause stenosis and only mild regurgitation. However, the patient also
required a single coronary-artery bypass.
Although previously referred to as CCMA, we want to propose a different
name, which better describes the lesion as an intracardiac mass, which
is derived from liquefaction of mitral annular calcifications(MAC):a MAComa . These lesions typically occur in the posterior mitral
annulus, and only rarely involve the anterior annulus. The exact
mechanism of liquefaction and caseation is not well understood but is
thought to be related to an altered Calcium phosphate metabolism, as its
prevalence is more common in end-stage renal failure
patients3. Moreover, lipid-laden macrophages are
implicated in the etiology of the liquefaction process, as these lesions
more frequently occur with higher serum cholesterol levels. The
condition can also be associated with bradyarrhythmias and/or
atrioventricular blocks, due to the proximity of the mitral valve
annulus to the conduction system3.