Caseous Calcification of the Mitral Annulus – A Sinister Cause of Cardioembolic Stroke Diagnosed by Cardiac MRI

Sir, In patients with infarcts in multiple arterial territories, cardioembolism should always be considered, and extensive work up should be done to ascertain the underlying etiology. We report a rare cardiac lesion that presented as a stroke and discuss the utility of cardiac magnetic resonance imaging (MRI) in its diagnosis. A 66-year-old lady, a hypertensive, presented with acute onset left upper and lower limb paresthesia, and weakness, with slurring of speech of 1 h duration. On examination, she had left hemianopia, upper motor neuron facial palsy, hemiparesis, and sensory dulling, with a National Institute of Health Stroke Scale Score (NIHSS) of 7. Her CT brain and CT angiogram were normal. After thrombolysis with IV alteplase, she recovered to NIHSS of 2. Her MRI brain done the next day showed acute infarct in the right posterior cerebral artery territory and tiny infarcts of varying ages in the bilateral middle cerebral artery territory. A transthoracic echocardiogram showed an immobile lesion attached to the posterior mitral leaflet (PML), without valve destruction that was reported as atrial fibroelastoma of size 14 × 8 mm after a transesophageal echocardiogram (TEE). Work up for infective endocarditis and malignancies were negative. Considering a cardioembolic stroke with infarcts in three arterial territories, she was initiated on oral anticoagulation with warfarin and planned for elective surgical excision with mitral valve replacement. But to confirm the diagnosis, a cardiac MRI was done that showed T1, T2W hypointense immobile lesion measuring 24 × 11 mm attached to base of PML with delayed peripheral contrast enhancement [Figure 1]. On CT correlation, the lesion showed peripheral hyperdense calcification with central hypodensity suggestive of caseous calcification of mitral annulus (CCMA). The patient was continued on oral anticoagulation alone and her surgery was canceled. At 3 months follow-up, she had almost completely recovered with no recurrent ischemic events.Figure 1: (a) Cardiac MRI T1W image showing hypointense lesion (yellow arrow) attached to the base of PML. (b) CT correlate of the lesion shows peripheral hyperdensity with central hypodensity (yellow arrow) suggestive of caseous calcification. (c) The lesion shows late gadolinium enhancement (yellow arrow). (d) Lesion shows no enhancement in perfusion imaging (yellow arrow)CCMA is a lesser-known variant of mitral annular calcification (MAC) with a prevalence of 0.06–0.07% in the population, seen among elderly individuals and those with hypertension, located most often in the PML.[1,2] The lesion is dynamic and has been reported to revert to MAC on follow-up.[1] It is a very rare cause of cardioembolic stroke that can be easily mistaken for a cardiac mass. Although TEE is the investigation of choice, it is not confirmatory. There is no clear consensus on its management as it is a benign condition usually, although anticoagulation is recommended in patients with embolic manifestation.[3] Mitral valve replacement is indicated only in complicated cases such as mitral valve dysfunction, conduction abnormalities, or other systemic embolization and when the possibility of a tumor could not be ruled out.[4] Our case highlights the utility of cardiac MRI in confirming the diagnosis missed by TEE, thereby avoiding the need for surgery. The caseous calcification of the mitral annulus is a rare cause of cardioembolic stroke. Cardiac MRI helped in the confirmation of diagnosis and planning treatment. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.