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Anterior mitral annulus caseoma: as benign as posterior counterparts?
Cardiovascular Pathology xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Cardiovascular Pathology
Case Report
Anterior mitral annulus caseoma: as benign as posterior counterparts? Alessandro Mazzucco a, Riccardo Abbasciano a, Francesco Onorati a,⁎, Gabriele Brognoli b, Diego Fanti a, Leonardo Gottin b, Giuseppe Faggian a a b
Division of Cardiac Surgery, University of Verona, Italy Postoperative Intensive Care Unit, University of Verona, Italy
a r t i c l e
i n f o
Article history: Received 7 August 2015 Received in revised form 27 September 2015 Accepted 6 October 2015 Available online xxxx Keywords: Mitral valve Mitral valve repair Echocardiography Caseoma Caseous calcification
a b s t r a c t 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. © 2015 Elsevier Inc. All rights reserved.
1. Introduction Caseous calcification of the mitral annulus (CCMA), also called “caseoma”, is considered a rare degenerative process of the annulus, in which a caseous degeneration of the “core” material into a “toothpaste-like” mixture of calcium, cholesterol, and fatty acids occurs [1]. CCMA is almost always described as a process involving the posterior mitral annulus [2]. A very rare involvement of the entire annulus has been also reported [2,3]. Isolated anterior annular involvement was not reported to date. Moreover, its incidental nature implies that it is rarely associated with valve dysfunction, usually a restrictive motion of the posterior mitral leaflet [2,4] or a “mass effect” responsible of mitral stenosis [1,5]. However, a severe mitral dysfunction mandating surgery is uncommon [1,5]. We report an exceptionally rare isolated anterior CCMA causing severe restrictive motion of the anterior leaflet responsible — together with a concurrent posterior leaflet prolapse — for a severe symptomatic mitral regurgitation. 2. Case report A 78-year-old man was admitted to our institution because of progressive dyspnea. Preoperative transthoracic echocardiography Conflict of interest: The authors declare that they have no conflict of interest. Funding: The authors declare that there is no financial support for the study or any other conflict of interest. No financial support exists for study design, collection analysis and interpretation of data, writing the report, and decision to submit article for publication. ⁎ Corresponding author. Division of Cardiac Surgery University of Verona, Piazzale Stefani n. 1, 37126 Verona, Italy. E-mail address: [email protected] (F. Onorati).
demonstrated a preserved left ventricular function and an anomalous mitral valve with an echo-dense, tumor-like mass (1.85 cm×1.76 cm, area 2.55 cm 2; Fig. 1A), with an internal central echo-lucent area — classified by the echocardiographer as a “common” annular calcification — located within the annular anterior region in the area of mitral aortic continuity (Fig. 1B) at the level of A1–A2 scallops of the anterior mitral leaflet and extending into the A1–A2 basal portion of the leaflet itself, close to the atrial wall. A systolic restrictive motion of the anterior leaflet was suspected. The mass showed sharp and distinct borders with different and bright echogenicity in comparison to the adjacent myocardium. The basal area of A1 and A2 scallops of the anterior leaflet appeared to be stretched and arched over the mass, whereas the posterior leaflet was prolapsing in its central P2 scallop (Fig. 1C) with a huge central jet (Fig. 1D); on Doppler color-flow scanning, a severe regurgitation was seen, without stenosis. Intraoperative transesophageal echocardiography confirmed these findings. Trivial calcifications of the free edge of the noncoronary aortic valve cusp and of the left coronary aortic valve cusp were also noticed at preoperative echocardiography, without concomitant calcification of the aortic annulus and with only a trivial aortic valve insufficiency not mandating surgery (Fig. 1B). Indeed, aortic valve analysis at surgery showed neither a “bulged mass” inside the aortic root annular area nor a calcified aortic annulus but only mild calcifications of the Arantius nodules. After longitudinal left atriotomy, external appearance of the CCMA mimicked a “common” mitral annular calcification, although it demonstrated — opposite to a “common” annular calcification — a toothpaste consistency related to a pasty white material filling the center of the nodule. A P2 quadrangular resection with posterior leaflet reconstruction according to Carpentier’s technique was executed. This initial repair failed
http://dx.doi.org/10.1016/j.carpath.2015.10.002 1054-8807/© 2015 Elsevier Inc. All rights reserved.
Please cite this article as: Mazzucco A, et al, Anterior mitral annulus caseoma: as benign as posterior counterparts? Cardiovasc Pathol (2015), http://dx.doi.org/10.1016/j.carpath.2015.10.002
2
A. Mazzucco et al. / Cardiovascular Pathology xxx (2015) xxx–xxx
Fig. 1. A large CCMA of the anterior leaflet (arrow, panel A) at mitral aortic fibrous curtain (arrow, panel B); a concurrent P2 scallop prolapse (arrow, panel C) contributes to a large central regurgitation (arrow, panel D).
to completely restore the mitral competence because a mass-related severe restrictive motion of the A1 scallop of the mitral leaflet — together with a trivial restrictive motion of its A2 scallop — was reported at intraoperative mitral valve analysis. The mass was sharply dissected, and the adjacent paracommissural segment of the anterior mitral leaflet (i.e. the basal area of the entire A1 scallop together with the lateral portion of the basal area of the A2 scallop) was resected and replaced with a small triangle of autologous glutaraldehyde-treated pericardium. Afterwards, a complete restoration of the physiological anterior mitral leaflet systolic movement was observed, resulting in excellent mitral valve coaptation at intraoperative “water test”. A posterior “exactly sized” pericardial mitral annuloplasty completed surgery. Pathological examination ruled out bacterial or fungal in-growth and reported a dense, amorphous
acellular and basophilic substance (Fig. 2A) with scattered calcifications (Fig. 2B) and sparse histiocytes, in the absence of inflammatory cells. Therefore, anterior mitral annular caseoma was diagnosed. Postoperative transesophageal echocardiography reported a normal mitral competence. Postoperative course was uneventful, and the patient was discharged on postoperative day 6. The patient is alive and in New York Heart Association class I at 10-month follow-up. 3. Discussion CCMA is considered a rare degenerative process of the annulus estimated to have an echocardiographic prevalence of 0.6% inside the spectrum of mitral annular calcification processes [5], of 0.068% in
Fig. 2. A large amorphous basophilic substance with rare histiocytes and calcified spots was reported (panel A: 100×, hematoxylin–eosin stain; calcified spots=purple spots — panel B: 200×, hematoxylin–eosin stain).
Please cite this article as: Mazzucco A, et al, Anterior mitral annulus caseoma: as benign as posterior counterparts? Cardiovasc Pathol (2015), http://dx.doi.org/10.1016/j.carpath.2015.10.002
A. Mazzucco et al. / Cardiovascular Pathology xxx (2015) xxx–xxx
large series [6], and of 2.7% in necropsies [3]. It is considered a rare variant of the common mitral annular calcification with which shares the etiology based on a chronic degenerative process involving calcium deposits of the fibrous skeleton of the heart [7]. Its common observation in elderly women and in patients with chronic renal failure or with calcium metabolism abnormalities (i.e. with higher “turnover” of calcium) seems to confirm this hypothesis [1,7]. However, the mechanisms involved in the caseous necrosis are still unknown, though both a hypercholesterolemia-based mechanism together with dissolution of lipid-laden macrophages and an atherosclerotic-like mechanism with progressive connective tissue degeneration leading to the formation of the CCMA as an “atheroma-like” lesion have been suggested [1,7,8]. Given its prevalent benign nature on mitral function, surgical observation is exceptional: Alkadhi et al. reported a functional mitral stenosis due to a huge posterior mitral caseoma [5], Pomerance describes only two cases requiring surgery [3] owing to an endocarditic complication of the caseous mass obstructing the mitral orifice, and GarciaIbarrondo et al. reported incidental diagnoses of posterior mitral caseous calcifications causing only mild mitral incompetence [1]. However, most of the other literature reports confirm that posterior CCMA only rarely hinders the physiological mitral function, and it is therefore considered benign in its clinical course. It should be stressed that the case here reported represents a very rare form of CCMA causing severe mitral regurgitation due to the combination of a functional restrictive effect exerted by CCMA on the anterior mitral leaflet systolic motion, together with a concurrent P2 prolapse, thus determining a huge central regurgitation rather than the more common eccentric regurgitant jet toward interatrial septum commonly seen in isolated P2 prolapse. Indeed, only the combination of anterior CCMA excision — which reestablished
3
a normal anterior leaflet motion — with a standard P2 prolapse surgery was able to restore mitral competence. The other peculiar aspect of the present case is the exceeding rarity of the anterior location. CCMA, has been to date reported almost always in posterior mitral annulus [1,2,4,5]. To the best of our knowledge, no other cases of CCMA with anterior location have been reported so far. In conclusion, the case reported adds a word of caution on the current trend to interpret CCMA as a “benign” and incidental echocardiographic finding. Indeed, this case demonstrated that CCMA has the potential for a direct and severe tethering effect on the adjacent mitral leaflet tissues, leading to mitral valve insufficiency. Furthermore, it demonstrates also that an exceptional rare isolated location on the anterior mitral annulus is possible. References [1] Garcia-Ibarrondo N, Lang RM. Caseous calcification of the mitral annulus, a rare echocardiographic finding. Rev Esp Cardiol 2011;64:828–31. [2] 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. [3] Pomerance A. Pathological and clinical study of calcification of the mitral valve ring. J Clin Pathol 1970;23:354–61. [4] Cagdas M, Sahan H, Velibey Y, Calik N, Sahin S. Huge mitral annular caseoma: complementary role of multimodality imaging. Echocardiography 2013;30:E138–40. [5] Alkadhi H, Leschka S, Pretre R, Perren A, Marincek B, Wildermuth S. Caseous calcification of the mitral annulus. J Thorac Cardiovasc Surg 2005;129:1438–40. [6] Novaro GM, Griffin BP, Hammer DF. Caseous calcification of the mitral annulus: an underappreciated variant. Heart 2004;90:388. [7] Pomeroy WL, Markelz B, Steel K, Slim AM. Mitral annular caseous calcification: a rare variant of a common echocardiographic finding discovered with advanced imaging techniques. Case Rep Med 2013;2013:972684. [8] Gramenzi S, Mazzola AA, Tagliaferri B, Protasoni G, Brusoni D, d’Aloya G, et al. Caseous calcification of the mitral annulus: unusual case of spontaneous resolution. Echocardiography 2005;22:510–3.
Please cite this article as: Mazzucco A, et al, Anterior mitral annulus caseoma: as benign as posterior counterparts? Cardiovasc Pathol (2015), http://dx.doi.org/10.1016/j.carpath.2015.10.002
Contents lists available at ScienceDirect
Cardiovascular Pathology
Case Report
Anterior mitral annulus caseoma: as benign as posterior counterparts? Alessandro Mazzucco a, Riccardo Abbasciano a, Francesco Onorati a,⁎, Gabriele Brognoli b, Diego Fanti a, Leonardo Gottin b, Giuseppe Faggian a a b
Division of Cardiac Surgery, University of Verona, Italy Postoperative Intensive Care Unit, University of Verona, Italy
a r t i c l e
i n f o
Article history: Received 7 August 2015 Received in revised form 27 September 2015 Accepted 6 October 2015 Available online xxxx Keywords: Mitral valve Mitral valve repair Echocardiography Caseoma Caseous calcification
a b s t r a c t 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. © 2015 Elsevier Inc. All rights reserved.
1. Introduction Caseous calcification of the mitral annulus (CCMA), also called “caseoma”, is considered a rare degenerative process of the annulus, in which a caseous degeneration of the “core” material into a “toothpaste-like” mixture of calcium, cholesterol, and fatty acids occurs [1]. CCMA is almost always described as a process involving the posterior mitral annulus [2]. A very rare involvement of the entire annulus has been also reported [2,3]. Isolated anterior annular involvement was not reported to date. Moreover, its incidental nature implies that it is rarely associated with valve dysfunction, usually a restrictive motion of the posterior mitral leaflet [2,4] or a “mass effect” responsible of mitral stenosis [1,5]. However, a severe mitral dysfunction mandating surgery is uncommon [1,5]. We report an exceptionally rare isolated anterior CCMA causing severe restrictive motion of the anterior leaflet responsible — together with a concurrent posterior leaflet prolapse — for a severe symptomatic mitral regurgitation. 2. Case report A 78-year-old man was admitted to our institution because of progressive dyspnea. Preoperative transthoracic echocardiography Conflict of interest: The authors declare that they have no conflict of interest. Funding: The authors declare that there is no financial support for the study or any other conflict of interest. No financial support exists for study design, collection analysis and interpretation of data, writing the report, and decision to submit article for publication. ⁎ Corresponding author. Division of Cardiac Surgery University of Verona, Piazzale Stefani n. 1, 37126 Verona, Italy. E-mail address: [email protected] (F. Onorati).
demonstrated a preserved left ventricular function and an anomalous mitral valve with an echo-dense, tumor-like mass (1.85 cm×1.76 cm, area 2.55 cm 2; Fig. 1A), with an internal central echo-lucent area — classified by the echocardiographer as a “common” annular calcification — located within the annular anterior region in the area of mitral aortic continuity (Fig. 1B) at the level of A1–A2 scallops of the anterior mitral leaflet and extending into the A1–A2 basal portion of the leaflet itself, close to the atrial wall. A systolic restrictive motion of the anterior leaflet was suspected. The mass showed sharp and distinct borders with different and bright echogenicity in comparison to the adjacent myocardium. The basal area of A1 and A2 scallops of the anterior leaflet appeared to be stretched and arched over the mass, whereas the posterior leaflet was prolapsing in its central P2 scallop (Fig. 1C) with a huge central jet (Fig. 1D); on Doppler color-flow scanning, a severe regurgitation was seen, without stenosis. Intraoperative transesophageal echocardiography confirmed these findings. Trivial calcifications of the free edge of the noncoronary aortic valve cusp and of the left coronary aortic valve cusp were also noticed at preoperative echocardiography, without concomitant calcification of the aortic annulus and with only a trivial aortic valve insufficiency not mandating surgery (Fig. 1B). Indeed, aortic valve analysis at surgery showed neither a “bulged mass” inside the aortic root annular area nor a calcified aortic annulus but only mild calcifications of the Arantius nodules. After longitudinal left atriotomy, external appearance of the CCMA mimicked a “common” mitral annular calcification, although it demonstrated — opposite to a “common” annular calcification — a toothpaste consistency related to a pasty white material filling the center of the nodule. A P2 quadrangular resection with posterior leaflet reconstruction according to Carpentier’s technique was executed. This initial repair failed
http://dx.doi.org/10.1016/j.carpath.2015.10.002 1054-8807/© 2015 Elsevier Inc. All rights reserved.
Please cite this article as: Mazzucco A, et al, Anterior mitral annulus caseoma: as benign as posterior counterparts? Cardiovasc Pathol (2015), http://dx.doi.org/10.1016/j.carpath.2015.10.002
2
A. Mazzucco et al. / Cardiovascular Pathology xxx (2015) xxx–xxx
Fig. 1. A large CCMA of the anterior leaflet (arrow, panel A) at mitral aortic fibrous curtain (arrow, panel B); a concurrent P2 scallop prolapse (arrow, panel C) contributes to a large central regurgitation (arrow, panel D).
to completely restore the mitral competence because a mass-related severe restrictive motion of the A1 scallop of the mitral leaflet — together with a trivial restrictive motion of its A2 scallop — was reported at intraoperative mitral valve analysis. The mass was sharply dissected, and the adjacent paracommissural segment of the anterior mitral leaflet (i.e. the basal area of the entire A1 scallop together with the lateral portion of the basal area of the A2 scallop) was resected and replaced with a small triangle of autologous glutaraldehyde-treated pericardium. Afterwards, a complete restoration of the physiological anterior mitral leaflet systolic movement was observed, resulting in excellent mitral valve coaptation at intraoperative “water test”. A posterior “exactly sized” pericardial mitral annuloplasty completed surgery. Pathological examination ruled out bacterial or fungal in-growth and reported a dense, amorphous
acellular and basophilic substance (Fig. 2A) with scattered calcifications (Fig. 2B) and sparse histiocytes, in the absence of inflammatory cells. Therefore, anterior mitral annular caseoma was diagnosed. Postoperative transesophageal echocardiography reported a normal mitral competence. Postoperative course was uneventful, and the patient was discharged on postoperative day 6. The patient is alive and in New York Heart Association class I at 10-month follow-up. 3. Discussion CCMA is considered a rare degenerative process of the annulus estimated to have an echocardiographic prevalence of 0.6% inside the spectrum of mitral annular calcification processes [5], of 0.068% in
Fig. 2. A large amorphous basophilic substance with rare histiocytes and calcified spots was reported (panel A: 100×, hematoxylin–eosin stain; calcified spots=purple spots — panel B: 200×, hematoxylin–eosin stain).
Please cite this article as: Mazzucco A, et al, Anterior mitral annulus caseoma: as benign as posterior counterparts? Cardiovasc Pathol (2015), http://dx.doi.org/10.1016/j.carpath.2015.10.002
A. Mazzucco et al. / Cardiovascular Pathology xxx (2015) xxx–xxx
large series [6], and of 2.7% in necropsies [3]. It is considered a rare variant of the common mitral annular calcification with which shares the etiology based on a chronic degenerative process involving calcium deposits of the fibrous skeleton of the heart [7]. Its common observation in elderly women and in patients with chronic renal failure or with calcium metabolism abnormalities (i.e. with higher “turnover” of calcium) seems to confirm this hypothesis [1,7]. However, the mechanisms involved in the caseous necrosis are still unknown, though both a hypercholesterolemia-based mechanism together with dissolution of lipid-laden macrophages and an atherosclerotic-like mechanism with progressive connective tissue degeneration leading to the formation of the CCMA as an “atheroma-like” lesion have been suggested [1,7,8]. Given its prevalent benign nature on mitral function, surgical observation is exceptional: Alkadhi et al. reported a functional mitral stenosis due to a huge posterior mitral caseoma [5], Pomerance describes only two cases requiring surgery [3] owing to an endocarditic complication of the caseous mass obstructing the mitral orifice, and GarciaIbarrondo et al. reported incidental diagnoses of posterior mitral caseous calcifications causing only mild mitral incompetence [1]. However, most of the other literature reports confirm that posterior CCMA only rarely hinders the physiological mitral function, and it is therefore considered benign in its clinical course. It should be stressed that the case here reported represents a very rare form of CCMA causing severe mitral regurgitation due to the combination of a functional restrictive effect exerted by CCMA on the anterior mitral leaflet systolic motion, together with a concurrent P2 prolapse, thus determining a huge central regurgitation rather than the more common eccentric regurgitant jet toward interatrial septum commonly seen in isolated P2 prolapse. Indeed, only the combination of anterior CCMA excision — which reestablished
3
a normal anterior leaflet motion — with a standard P2 prolapse surgery was able to restore mitral competence. The other peculiar aspect of the present case is the exceeding rarity of the anterior location. CCMA, has been to date reported almost always in posterior mitral annulus [1,2,4,5]. To the best of our knowledge, no other cases of CCMA with anterior location have been reported so far. In conclusion, the case reported adds a word of caution on the current trend to interpret CCMA as a “benign” and incidental echocardiographic finding. Indeed, this case demonstrated that CCMA has the potential for a direct and severe tethering effect on the adjacent mitral leaflet tissues, leading to mitral valve insufficiency. Furthermore, it demonstrates also that an exceptional rare isolated location on the anterior mitral annulus is possible. References [1] Garcia-Ibarrondo N, Lang RM. Caseous calcification of the mitral annulus, a rare echocardiographic finding. Rev Esp Cardiol 2011;64:828–31. [2] 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. [3] Pomerance A. Pathological and clinical study of calcification of the mitral valve ring. J Clin Pathol 1970;23:354–61. [4] Cagdas M, Sahan H, Velibey Y, Calik N, Sahin S. Huge mitral annular caseoma: complementary role of multimodality imaging. Echocardiography 2013;30:E138–40. [5] Alkadhi H, Leschka S, Pretre R, Perren A, Marincek B, Wildermuth S. Caseous calcification of the mitral annulus. J Thorac Cardiovasc Surg 2005;129:1438–40. [6] Novaro GM, Griffin BP, Hammer DF. Caseous calcification of the mitral annulus: an underappreciated variant. Heart 2004;90:388. [7] Pomeroy WL, Markelz B, Steel K, Slim AM. Mitral annular caseous calcification: a rare variant of a common echocardiographic finding discovered with advanced imaging techniques. Case Rep Med 2013;2013:972684. [8] Gramenzi S, Mazzola AA, Tagliaferri B, Protasoni G, Brusoni D, d’Aloya G, et al. Caseous calcification of the mitral annulus: unusual case of spontaneous resolution. Echocardiography 2005;22:510–3.
Please cite this article as: Mazzucco A, et al, Anterior mitral annulus caseoma: as benign as posterior counterparts? Cardiovasc Pathol (2015), http://dx.doi.org/10.1016/j.carpath.2015.10.002