Mitral regurgitation due to caseous calcification of the mitral annulus: two case reports
© Marcì and Lo Jacono; licensee BioMed Central Ltd. 2009
Received: 11 December 2008
Accepted: 29 January 2009
Published: 29 January 2009
Caseous calcification is a rare variant of mitral annular calcification, occurring in about 0.06% of echocardiographic studies performed. It is usually a benign lesion, but it should be differentiated by abscess and tumors. Echocardiography is the most sensitive method to identify caseous calcification which appears typically as a round, calcified mass with an echo-lucent, liquid-like inner part.
Unlike mitral annular calcification (MAC), that is a common echocardiographic finding, caseous calcification is a rare variant, occurring in about 0.6% of patient with annular calcification [1–3]. Patient 1.
An 82-year-old woman, with history of hypertension, was admitted to our department for paroxystic atrial fibrillation, which was successfully treated with intravenous Amiodarone. Physical examination revealed a systolic murmur of 2–3/6 L grade. Besides laboratory examinations were substantially normal.
Colour-Doppler examination ruled out shunt between the cyst and the cardiac chambers, moreover colour flow mapping revealed a moderate mitral insufficiency without mitral stenosis. Transesophageal echocardiogram was refused by the patient.
Since there was not dyspnoea, nor left ventricular dilatation, conservative treatment and follow up was considered sufficient.
MAC is a common finding, especially in the elderly and in the end-stage renal failure [1–5]. Calcification begins between the posterior atrio-ventricular groove and the base of posterior mitral leaflet, although in very elderly subjects it can involve the entire annulus. Otherwise caseous calcification represents a rare evolution of a calcified mitral ring, due to caseous transformation of the inner material.
Histological examination of the inner fluid usually reveals an amorphous, basophilic content, composed by a blend of calcium and cholesterol, surrounded by a inflammatory cells, mainly macrophages [3–5]. Echocardiography has demonstrated to be the most reliable method to diagnose this lesion. Almost invariably, caseous calcification appears as an echo-dense, round, smooth mass with a liquid core, surrounded by a calcified envelop, as a rule it is localized into the posterior mitral annulus [1–3, 6]. Further exams, such as transesophageal echocardiography, computed tomography and magnetic resonance, are seldom necessary to differentiate caseous calcification from tumour or abscess . In fact the latter condition usually causes fever and embolic events. Besides caseous calcification has a more calcified envelope than infected mitral ring .
Caseous calcification is a rare, accidental echocardiographic finding, occurring in about 0, 06% of all echocardiographic studies [3–6], whereas it has a higher prevalence in a necropsy series . This discrepancy could be explained by the fact that this condition could not be recognised by cardiologists that are unfamiliar with this unusual lesion. It is of interest that this pathological condition is mentioned as sterile caseous abscess of mitral ring in a widely diffuse textbook of echocardiography  and it is neglected by a recent review of echogenic structures .
Caseous calcification is a benign condition, which only rarely may determine significant valvular stenosis or insufficiency, requiring surgical treatment [3–6, 9]. As a rule conservative management is indicated in most of the cases [1–3].
The authors state that informed written consents were obtained from both the patients for publication of manuscript and figures.
- Novaro GM, Griffin BP, Hammer DF: Caseous calcification of the mitral annulus: an underappreciated variant. Heart;. 2004, 90 (4): 388-10.1136/hrt.2003.023010.View ArticlePubMedPubMed CentralGoogle Scholar
- Arora H, Madan P, Simpson L, Stainback RF: Caseous calcification of the mitral annulus. Tex Heart Inst J. 2008, 35 (2): 211-213.PubMedPubMed CentralGoogle Scholar
- Harpaz D, Auerbach I, Vered Z, Motro M, Tobar A, Rosenblatt S: Caseous calcification of the mitral annulus: a neglected, unrecognized diagnosis. J Am Soc Echocardiogr. 2001, 14: 825-831. 10.1067/mje.2001.111877.View ArticlePubMedGoogle Scholar
- Pomerance A: Pathological and clinical study of calcification of the mitral valve ring. J Clin Pathol. 1970, 23: 354-361. 10.1136/jcp.23.4.354.View ArticlePubMedPubMed CentralGoogle Scholar
- Sheppard M, Davies M: Practical cardiovascular pathology. 1998, New York. Oxford University Press, 86.Google Scholar
- Kronzon I, Winer HE, Cohen ML: Sterile, caseous mitral annular abscess. J Am Coll Cardiol. 1983, 2: 186-190.View ArticlePubMedGoogle Scholar
- Feigenbaum H: Echocardiography. 1994, Lea & Febiger, 329-5Google Scholar
- Zuber M, Oechslin E, Jenni R: Echogenic structure in the left atrioventricular groove: diagnostic pitfalls. J Am Soc Echocardiogr. 1998, 11: 381-386. 10.1016/S0894-7317(98)70107-5.View ArticlePubMedGoogle Scholar
- Minardi G, Manzara C, Pulignano G, Pino PG, Pavaci H, Sordi M, Musumeci F: Caseous calcification of the mitral annulus with mitral regurgitation and impairment of functional capacity: a case report. Journal of Medical Case Reports. 2008, 2: 205-209. 10.1186/1752-1947-2-205.View ArticlePubMedPubMed CentralGoogle Scholar
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