https://orcid.org/0000-0001-8024-5566
Abstract
A 70-year-old woman with heart failure and end-stage renal disease on dialysis was found to have a 2.9 cm × 0.9 cm swinging mass attached to the posterior wall of the ascending aorta, 3 cm above the aortic valve. Due to the risk of embolization, she underwent an aortotomy and mass excision. The mass had extensive calcifications with degenerative changes and no evidence of malignancy. This represents an exceedingly rare location for a calcified amorphous tumour. Our review adds to the literature establishing the proximal aorta as a characterized location for a calcified amorphous tumour and provides a treatment approach to prevent embolization.
INTRODUCTION
Calcified amorphous tumour (CAT) was originally characterized in 1997 by Reynolds et al. [1] as an intracavitary mass consisting of calcification and fibrous material. Since then, a systematic review in 2015 found the most common location to be the mitral valve or annulus [2]. To date, there have only been 2 described cases of a CAT in the ascending aorta [3, 4]. We report a third case of ascending aorta CAT. Due to its risk of embolization, CAT was removed via transverse aortotomy and resection. The patient was stable without evidence of transient ischaemic attack or cerebrovascular accident at 6-month follow-up.
CASE
A 70-year-old patient with the past medical history of end-stage renal disease (ESRD) and heart failure with preserved ejection fraction presented to the emergency department prior to her scheduled dialysis session with nonspecific symptoms. In the emergency department, she was hypotensive, hyperkalemic and her troponins were elevated. The patient underwent cardiac and stroke workup due to altered mental status and laboratory findings. Workup was negative for acute infarction or stroke. It was determined that the patients’ acute mental status alteration was related to her elevated blood urea nitrogen, creatinine and potassium. The patient was stabilized and sent for dialysis and an echocardiogram was ordered.
Transthoracic echocardiography revealed a normal ejection fraction and a mobile 3-cm aortic mass that moved with variations in the cardiac cycle. Mitral annular calcification was also seen. At that time, possible explanations included aortic endocarditis, aortic mural vegetation, ascending dissection or a non-infectious aortic mass. Computed tomography angiography thorax followed which did not demonstrate a dissection flap. Computed tomography of the heart showed no coronary artery disease and demonstrated a calcified mass in the ascending aorta (Fig. 1A). Subsequent blood cultures were negative and transoesophageal echocardiography redemonstrated a 2.9 cm × 0.9 cm mobile mass on the posterior wall of the ascending aorta above the aortic valve with diffuse calcification (Video 1).
Due to the risk of embolization, cardiac surgery was planned. The patient was placed on cardiopulmonary bypass and the aortic cannula was placed in the transverse arch above the mass. Transverse aortotomy was made and the attached calcification mass was removed (Fig. 1B). A 3-cm section of the posterior wall of the ascending aorta was resected, which contained the attachment point for the mass. The aorta was reapproximated and the patient was weaned from cardiopulmonary bypass.
The removed mass was characterized by extensive calcifications with degenerative changes and was diagnosed as a CAT (Fig. 2). The patient was discharged to a rehabilitation facility and had no neurologic or peripheral embolic events during the 6-month follow-up period.
Computed tomography showing proximal aortic calcified mass (A). Intraoperative image showing mass (B).
Macroscopic finding of the mass after resection (A). Histologic findings (hematoxylin and eosin stain) of the mass (B).
Transthoracic echocardiograph showing swinging calcified mass in proximal ascending aorta with variations in the cardiac cycle.
DISCUSSION
Due to its rarity, cardiac CAT provides both a diagnostic and therapeutic challenge to the clinician. In addition, the ascending aorta is rarely the source of emboli and less studied with only 2 previously described cases reported [3, 4]. While surgery is often needed for definitive diagnosis, the clinical picture may allow for distinguishing other entities in the differential diagnosis including aortic dissection, infectious endocarditis and non-infectious aortic masses. In the case of type 1 dissection, the computed tomography angiography thorax would be diagnostic. Circumferential separation of the intima and media may roll back into the ascending aorta appearing similar to a cardiac CAT on imaging, but clinical features may include chest pain, signs of malperfusion and aortic insufficiency. Infectious aetiology can be distinguished due to the presence of fever and positive blood cultures and must be treated initially with anti-microbials. Non-infectious aortic masses include thrombus and mobile masses such as papillary fibroelastoma or Lambl’s excrescences. A history of prior embolic events would warrant surgical resection. In this patient, the presence of calcifications on imaging, lack of other clinical findings and concern for embolization led to the decision for surgery.
This case provides the third example of an association between patients on long-term haemodialysis with other visualized cardiac calcifications, i.e. mitral annular calcifications, and a mobile calcified mass in the proximal aorta [3, 4]. This association adds to the previously described reports of rapid growing and mobile CAT in patients on ESRD, albeit in a different location [5]. A systematic review by de Hemptinne et al. [2] found that the most common associations with CAT were valvular disease (31%) and ESRD (21%). This cluster of findings may assist the physician with diagnosis.
The risk of embolization of any cardiac CAT is high and was reported in 31% of cases [2]. This number is likely to be underreported as many patients undergo operation shortly after the time of diagnosis. Both Ishida et al. [3] and Kubota et al. [5] described the tumour to be fragile and easily removed during operation. The swinging, or mobile, subgroup of CAT in conjunction with mitral annular calcification may be at higher risk for embolization and has been characterized separate from immobile masses [2, 5]. We suspect that this aortic subtype may pose an even higher risk of embolization due to the high pressures in the proximal aorta, necessitating the need for treatment.
In 1 case, the ascending aortic mass was removed during a period of circulatory arrest [3]. This case represents the second reported case employing aortotomy after cross-clamping the aorta [4]. Both prior cases reported good outcomes at follow-up. In this case, thoughtful consideration and preoperative evaluation of this rare entity led to successful operative removal and the prevention of complications including embolization.
Conflict of interest: none declared.
SUPPLEMENTARY MATERIAL
Supplementary material is available at EJCTS online.
Reviewer information
European Journal of Cardio-Thoracic Surgery thanks Ruggero De Paulis and the other, anonymous reviewer(s) for their contribution to the peer review process of this article.
