Mitral annular caseous calcification: a rare variant of a common echocardiographic finding discovered with advanced imaging techniques

Caseous Calcification of the Mitral Annulus Associated with Severe Mitral Regurgitation: A Multimodality Diagnostic Approach

Caseous calcification of the mitral annulus (CCMA) is a rare variant of mitral annular calcification, and a multimodality approach is advised to ensure an accurate diagnosis. We report a case of a patient with CCMA, associated with severe mitral regurgitation. An 82-year-old woman was admitted due to worsening heart failure. Transthoracic echocardiography revealed a fixed, hyperechogenic mass, accompanied by restriction of the posterior mitral leaflet, and subsequent severe mitral regurgitation. Transesophageal echocardiography demonstrated a restricted motion of the posterior mitral leaflet, because of a large, echogenic mass (15 mm × 11 mm), attached to the mitral annulus, vacuolated with a central echolucent aspect, lacking acoustic shadowing. Contrast-enhanced cardiac computed tomography identified a distinct oval mass (18 mm × 11 mm × 19 mm) presenting a central hypodense content and peripheral calcification, strongly suggestive of CCMA. Considering the patient's profile, surgical valvular replacement was considered unsuitable. Therefore, a transcatheter edge-to-edge repair was performed, resulting in mild residual regurgitation.

Ruptured caseous calcification of the mitral annulus

Mitral annular calcification (MAC) is considered a chronic and degenerative process involving the fibrous annulus of the mitral valve. The prevalence of MAC has been reported between 8% and 15%. It significantly increases with age, often seen in females, individuals with hypertension, chronic kidney disease and those with multiple cardiovascular risk factors. Caseous calcification of the mitral annulus (CCMA) (also known as caseoma) is a rare variant of MAC and should be considered in the differential diagnosis with other cardiac masses of the mitral valve. An 85-year-old female presented for a transthoracic echocardiogram with a history of hypertension and a systolic murmur. The echocardiogram demonstrated a possible rare variant of MAC, with independent mobile echodensities identified. Further testing using transoesophageal echocardiography was used to confirm diagnosis and ensure appropriate clinical management was arranged. This case demonstrated CCMA, a benign condition that can be mistaken for cardiac tumours, thrombus, vegetations or abscesses. A low prevalence has been reported between 0.06% and 0.07% and 0.6% of patients with MAC using echocardiography. Echocardiography can provide the initial diagnosis for identification and characterisation of MAC. CCMA appears as a calcified mass with an echolucent, liquid-like inner part, located on the posterior mitral valve annulus. Acoustic shadowing is usually absent. Multi-modality imaging can lead to an accurate diagnosis of CCMA without unnecessary interventions. Transoesophageal echocardiography provides further information on the site and composition of the internal material. Computed tomography (CT) and cardiac magnetic resonance imaging (MRI) can also be used, to confirm the diagnosis and to exclude other differential diagnoses.

Caseous calcification of the mitral annulus: case report and brief review

Background

Caseous calcification of the mitral annulus (CCMA) is a very rare variant of mitral annular calcification, which is typically asymptomatic but can manifest as a cardiac tumour, abscess, or in the form of mitral valve dysfunction.

Case summary

We present a patient who developed shortness of breath and was initially thought to have an intracardiac tumour, but ultimately was recognized as massive calcification of the mitral valve by computed tomography angiogram. This finding was unfortunately made only shortly before the patient’s clinical deterioration, and the specific diagnosis of CCMA was made on post-mortem findings, precluding any directed treatment for this entity.

Discussion

Caseous calcification of the mitral annulus can lead to significant pathology, including mitral regurgitation, stenosis, or systemic embolization of caseous material. Due to its relative scarcity and tendency to be asymptomatic, a diagnosis of CCMA is often difficult to make or easily overlooked. Early recognition and appropriate treatment is crucial for avoiding these potential complications.

Anterior mitral annulus caseoma: as benign as posterior counterparts?

Mitral annular caseoma is a common incidental finding involving the posterior annulus. It has an innocent nature, with the exception of its endocarditic degeneration and/or a stenotic functional effect when exophytic. We report an exceptionally rare isolated anterior mitral annular caseoma involving also the anterior mitral leaflet and affecting its physiologic systolic movement, thus resulting in a restricting anterior leaflet motion responsible for mitral insufficiency. The case was successfully treated by complex mitral valve repair.

A large cardiac mass: diagnosis of caseous mitral annular calcification and determining optimum management strategy

A 64-year-old woman with dizziness and blurry vision underwent an evaluation for a possible stroke with a head-neck CT scan and a transthoracic echocardiogram. The head-neck CT scan was unremarkable, but the echocardiogram was notable for a 2.0 × 2.3 cm heterogeneous echodensity attached to the mitral valve. After a transesophageal echocardiogram and chest CT scan, the mass was determined to be a caseous mitral annular calcification, CMAC. This entity is a rare variant of MAC with an estimated prevalence of 0.068%. Echocardiographic techniques can distinguish CMAC from other intracardiac masses such as tumor, cyst, or abscess. CMAC is associated with cerebrovascular accidents; however, optimal treatment is controversial given the rarity of this clinical finding. Management strategies should be tailored based on the patient's presentation, risk factors, and overall clinical circumstances.