A case of cardiac mass attached to the mitral annulus in an octogenarian male patient (QF_FR_078)

An 82-year-old male with no previous medical history complained of palpitations the last 2 months. There was no previous history of cardiovascular or respiratory disease.
The patient initially underwent a clinical examination which was unremarkable. The patient underwent an echocardiogram which showed a large well-defined, echo-dense mass with central echolucency surrounded by a calcified envelope adjacent to the mitral valve annulus.  The patient was referred for a cardiac MRI study for further assessment.  

Diagnostic Techniques and Their Most Important Findings:

.  An irregular shaped heterogeneous lobular mass which measured 24x46x35mm attached on the ventricular side of the posterior mitral valve leaflet, originating from the level of the mitral annulus and extended to the free edge of the leaflet was noted. The mass was not mobile, it followed the motion of the posterior mitral valve leaflet which was significantly restricted. The mass had similar signal intensity to the myocardium on bSSFP and T1w sequences, and low signal on T1-SPIR, T2w and STIR-T2 images. There was no increase of signal intensity during dynamic first pass perfusion while in late enhancement images (LGE) there was peripheral enhancement with low signal intensity centrally. These findings were suggestive of caseous calcification of the mitral valve. An ECG triggered CT scan without iodine contrast infusion which followed, showed a calcified mass with slightly hypodense central area. These findings supported the diagnosis of caseous calcification of the mitral valve. The differential diagnosis included valvular benign tumors such as papillary fibroelastoma, myxoma or lipomatous hypertrophy, malignant masses such as angiosarcoma or metastases as well as thrombus. The lack of mobility, the presence of extensive calcification as well as the lack of enhancement at the dynamic and LGE images made all the above diagnoses less possible.

Learning Points from this Case:

Caseous mitral annular calcification (CMAC) is a rare variant of degenerative mitral annular calcification (MAC). It primarily affects older patients with hypertension, with an overall prevalence of up to 0.07% in the general population (1,2). Due to the general benign prognosis, conservative management of this lesion is performed in most cases. However, CMACs may grow large in size and infiltrate adjacent territories such as the myocardium. CMAC rarely was linked to severe mitral valve dysfunction, transient aortic outflow tract obstruction, embolization, heart block, or constrictive pericarditis (3). Differentiation of a CMAC from other cardiac masses attached to the mitral annulus may be challenging. A multimodal imaging approach with echocardiography, cardiac CT imaging, and cardiac magnetic resonance (CMR) is normally used to access the diagnosis.

References

< ![if !supportLists] >1.    < ![endif] >1. Deluca G, Correale M, Ieva R, Del Salvatore B, Gramenzi S, Di Biase M. The incidence and clinical course of caseous calcification of the mitral annulus: a prospective echocardiographic study. J Am Soc Echocardiogr 2008;21:828–33. 2.

< ![if !supportLists] >2.    < ![endif] >Pomerance A. Pathological and clinical study of calcification of the mitral valve ring. J Clin Pathol 1970;23:354–61.

< ![if !supportLists] >3.    < ![endif] >3. Motwani M, Fairbairn TA, Jogiya R, Greenwood JP, Plein S. Caseous calcification of the mitral valve complicated by embolization, mitral regurgitation, and pericardial constriction. Eur Heart J Cardiovasc Imaging 2012;13:792.