An asymptomatic 76-year-old woman with a prior history of mitral annular calcification
underwent a transthoracic echocardiographic examination for evaluation. Her risk factor
for atherothrombotic disease was hypertension, and she had no prior medical history
of hyperlipidemia or diabetes. She was given the following pharmacologic treatments:
an angiotensin-converting enzyme (ACE) inhibitor (quinapril 5 mg), a calcium antagonist
(lercanidipine 10 mg), a loop diuretic (furosemide 25 mg), and an antiplatelet agent
(acetylsalicylic acid 150 mg). A round, echo-dense structure was visualized in the
left atrioventricular groove region (Fig. 1, upper panels). A transesophageal echocardiographic
examination (TEE) was performed to better evaluate this intracardiac mass (Fig. 1,
lower panels). A large (2.14 × 1.82 cm), round, echo-dense mass containing central
areas of echolucencies (central liquefaction) was revealed by TEE. No acoustic shadowing
could be detected behind the mass, suggesting an absence of dense calcium deposition.
The mass had sharp and distinct borders, with an echogenicity distinct from that of
the adjacent myocardium (Fig. 2, left panel). The echocardiographic findings were
consistent with the diagnosis of Caseous Calcification of the Mitral Annulus (CCMA).
The patient was asymptomatic and was treated conservatively. A TEE conducted nine
months later revealed the disappearance of the mass (Fig. 2, right panel).
Mitral Annular Calcification (MAC) is a chronic degeneration of the mitral valve fibrous
ring involving the posterior annulus. This disorder is common in the elderly, particularly
in women.1 It may also occur in younger patients with advanced renal disease or other
metabolic disorders that result in abnormal calcium metabolism. MAC is a consequence
of atherosclerosis, with risk factors identical to those of cardiovascular disease.
CCMA is a less-known and rarely described entity. This condition is an extensive “soft”
periannular calcification, resembling a tumor, that is composed of an admixture of
calcium, fatty acids, and cholesterol with a “toothpaste-like texture.” CCMA is often
misdiagnosed as a myocardial abscess,2,3 a tumor,4,5,6 or a thrombus,7 in some cases2
leading to unnecessary explorative cardiotomy. Differential diagnosis of round echogenic
structures adjacent to the left atrioventricular groove should also include infected
mitral calcification, lipomatosis of the atrioventricular groove, and enlarged lymph
nodes.8 In this case, a correct diagnosis was made according to clinical presentation
and echocardiographic findings. Generally, valvular endocarditis is unlikely in the
absence of mitral valve regurgitation, fever, or positive blood cultures or laboratory
examinations for infectious disease. Clinical signs of malignancy were absent. The
round, echodense lobular aspect and mobility of the mass favored the diagnosis of
myxoma; however, myxomas seldom originate from valves and are often found attached
to the inter-atrial septum in the fossa ovalis region. Instead, specific echocardiographic
features of CCMA favor the diagnosis: a large, round echodense mass in the posterior
periannular mitral region that is heterogeneous and contains central echolucent areas
of necrosis. The density of the mass suggested calcification and ruled out a thrombus
Harpaz and colleagues conducted a prospective series of echocardiographic examinations
to define the echocardiographic appearance, prevalence, and prognosis of CCMA.9 They
described the typical echocardiographic appearance of CCMA as a large, round, echo-dense
mass with smooth borders situated in the periannular region, lacking acoustic shadowing
artifacts, and containing central areas of echolucencies resembling liquefaction.
They emphasized that it is possible to make a correct diagnosis by transthoracic examination
alone, since no additional significant information was obtained by TEE in the 19 cases
they examined. In this patient, however, TEE gave a more precise and detailed image
of the mass and a better definition of the motion of the posterior mitral leaflet.
Recently, we10 have confirmed that CCMA is a rare and benign condition (14 patients
with CCMA, 0.64% of all mitral annular calcifications, 0.068% of all studies). This
study revealed no clinical characteristics typical of patients with CCMA. However,
CCMA did tend to occur in older patients, and all 14 patients with CCMA had hypertension.
We suggested that CCMA may be a dynamic process based on the observation that three
patients with MAC progressed to CCMA and three patients with CCMA reverted back to
MAC during the study period.
It is important to differentiate between CCMA and MAC; the former is a larger, well-delineated
structure surrounded by clear borders with a distinct echolucency and a “softer” appearance
that is less reflective and does not have acoustic shadowing. When a CCMA is perforated,
a large amount of toothpaste-like, milky, caseous material is exuded from the mass.
This material it is not truly calcific, but rather consists of caseous, putty-like
material. After the material is removed, only a calcified envelope remains. In the
case of large dense deposits of calcifications in the left atrioventricular groove,
significant acoustic shadowing artifacts may rule out the diagnosis of CCMA. However,
if the calcified envelope of the CCMA is very large, acoustic shadowing could result
in an erroneous non-diagnosis of CCMA.10
The mechanisms involved in the liquefaction necrosis of CCMA are not well understood.
Hypercholesterolemia and dissolution of lipid-laden macrophages might be implicated;
high serum cholesterol is associated with MAC and may be responsible for liquefaction
The peculiarity of this case is in its spontaneous resolution ten months later. A
previous similar case11 in the literature showed a spontaneous resolution of a CCMA.
In this previous case, the patient had a prior history of hemodialysis treatment,
but no change was made in the hemodialysis regimen. In another similar case12 with
a prior history of hemodialysis treatment, the reduction of the mass was observed
after treatment with low calcium hemodialysis, so the authors suggested that the acute
change in the serum calcium level might have contributed to the dissolution of the
mass. In our case, we hypothesize that central liquefaction and dissolution of the
material through a rupture of external wall occurred without evident clinical consequences.
In order to avoid misdiagnoses of CCMA as tumors, abscesses, or thrombi by echocardiographers,
it is important that knowledge of this rare lesion becomes more widespread.