1. Abstract Cardiac myxomas are the most common primary cardiac tumor. Clinical findings are numerous and range from general manifestations to symptoms related to intra-cardiac obstruction or systemic embolization. Echocardiography is the key exam for the diagnosis and surgery allows tumor resection and the prevention of complications.
Keywords: Myxoma; Cardiac tumor; Cardiac mass; Imaging
2. Introduction Cardiac myxomas are the most common benign primary cardiac tumors. About 75% are found in the left atrium, 20% in the right atrium, and 5% in the ventricles [1]. Typically, they are solitary and arise from a pedicle on or near the fossa ovalis. They occur more in females and after the third decades of life [2]. The tumor can cause intracardiac obstruction and systemic or pulmonary embolization [3,4]. The preoperative diagnosis of such tumors has been facilitated by the advent of echocardiography and is confirmed by histology. Surgical resection results improved by the advances in cardiac operations and procedures.
3. Cases Presentation We present four cases of cardiac myxoma. Case 1: A 58-year-old female with history of diabetes mellitus and hypertension, presented to the emergency department with transcient right hemiparesia and left facial paralysis, with a history of two similar reversible episodes three weeks before. Cerebral and thoraco abdominal Computed Tomography (CT) scan was performed revealing an acute ischemic stroke of the right middle cerebral artery and hepatic infract. Electrocardiogram (ECG) demonstrated normal sinus rhythm with negative T-wave in antero-septal territory. A Transthoracic Echocardiography (TTE) was performed, showing a giant hyperechoic oval mass measuring 62x33 mm. This mass was appended to the inter-atrial septum in its middle part and prolapsing in the left ventricle during diastole and almost totally obstructing blood flow. The mean pressure gradient through the mitral valve was 13 mmHg with a maximum measurement of 23 mmHg (Figure 1). Left atrium was dilated by the mass and systolic pulmonary arterial pressure (SPAP) was estimated by tricuspid regurgitation flow at 48 mmHg. The patient underwent cardiac surgery using cardiopulmonary bypass with a successful resection of the atrial mass. The postoperative period was uneventful, echocardiographic control showed a PAP normalization with no residual tumor. Histological examination confirmed the diagnosis of myxoma. The patient was discharged from the hospital on day 9 without symptoms. The 24 months echocardiographic follow up did not show any signs of recurrence.
Case 2: A 52 years old female, without any medical history, presented to the emergency department for a prolonged loss of consciousness for five hours with aphasia and abdominal pain. Immediat cerebral CT scan showed left cortico-subcortical hypodensity ranges located in fronto-parieto-occipital regions, associated with bilateral thalamic lacunar hypodensities in favor of multiple supratentorial cerebral strokes of different ages. Abdominal CT angiography revealed peripheral renal and splenic hypodense areas suggestive of infarcts. ECG demonstrated normal sinus rhythm with normal repolarization. Transthoracic echocardiography revealed a thickening of the inter-atrial septum with probable adherent thrombus measuring 5 mm adherent thrombus. Transesophageal echocardiogram was performed for a finer study of atrial septum anatomy. It showed an echogenic oval and not very mobile mass measuring 25*15mm with a wide implantation base, attached on the left side of the atrial septum, on which a thrombus of 5 mm length is appended (Figure 2). The patient underwent surgical resection of the mass using cardiopulmonary bypass. The patient underwent a surgical resection of the mass without any incident. The anatomopathological examination revealed myxoid tumor proliferation with calretinin-expressing tumor cells, this morphological and immunohistochemical appearance was consistent with cardiac myxoma. 6 months echocardiographic follow up didn’t show any recurrence of cardiac myxoma.
Case 3: A 58 years old female with a history of diabetes and hypertension, presented to the emergency department for aggravating dyspnea associated with fever and cough evolving few days before here consultation without any embolization signs. A COVID-19 PCR test was performed given these signs and the context of COVID-19 pandemic who turned out to be positive. The patient was admitted in an intensive care unit for 15 days. A routine and systematic echocardiographic evaluation was carried out and revealed a homogeneous echogenic, elongated, mobile LA mass, measuring 65*19mm. This mass was appended to the inter-atrial septum and prolapsing into the left ventricle during diastole, without obstruction the mitral valve. Mean trans-mitral pressure gradient was 3.2 mmHg (Figure 3). The patient underwent cardiac surgery with complete resection of the mass. The histological examination showed a regular myxoid pauci-cellular proliferation. The mucoid substance is homogeneous eosinophilic, this morphological aspect corresponds to a myxoma. Post operative and 2 months echocardiographic control haven’t show any residual mass.
Case 4: A 52 years old male with a history of diabetes, tabacco use and hypertension, presented for dyspnea on exertion since few mounths. Physical examination revealed right heart failure signs with bilateral lower limbs edema, basal right pleural effusion syndrome, pericardial friction rub. The ECG showed a diffuse microvoltage. chest X-ray revealed a moderate right pleural effusion. Transthoracic echocardiography showed a huge echogenic mass filling the entire RA measuring 80*62mm. This mass appeared to be appended to the atrial septum and was obstructing the tricuspid valve during diastole. The mean pressure gradient through the tricuspid valve was 12 mmHg. There was a pericardial effusion of medium abundance towards the right ventricle (Figure 4). There was no evidence for pulmonary embolism on thoracic computed tomography (CT) angiography. Tumor markers were all negative and the Body CT didn’t show any primary or secondary tumor locations other than this mass. Cardiac surgery was carried out after a normal coronarography, the mass appeared attached to the right side of atrial septum during intraoperative assessment. Anatomopathological study showed a myxoid tumor proliferation. Dyspnea and right heart failure signs regressed after cardiac resection surgery with no recurrence on echocardiographic control at one year.
4. Discussion Cardiac myxoma is the most common ‘benign’ cardiac tumor and may have varying clinical presentations. The classic triad of clinical presentation includes: obstructive cardiac symptoms; embolic signs and symptoms; and constitutional or systemic manifestations. Although the identification of cardiac masses is usually made using imaging, the final diagnosis of cardiac myxoma is confirmed following surgical resection of the cardiac tumor and histopathological assessment of the sample [5]. Cardiac myxoma is rare in children and is less frequent in blacks [6]. It can occur at any age but are most common age interval is between 30 and 60 years, with a female predominance [7]. The mean age of our four patients was 55 years at the time of surgery and three of our patients were female which agrees with data from the literature. Cardiac myxoma is located in 75% of cases in the left atrium (LA), 23% in the right atrium (RA), and only 2% in the ventricles. The most common site of attachment is the fossa ovalis. Multiple locations are not very common, but can be present in 50% of familial forms [8]. In our patients, three cases had a left atrial location and one case involved a right atrial myxoma. Clinical manifestations of cardiac myxoma are numerous, they depend on the location, shape, size, growth rate and friability of the tumor. They can be related to intra-cardiac obstruction including signs of dyspnea, orthopnea, malaise, palpitations or syncope, or they can be may be secondary to systemic emboli [9] which are either tumoral when the myxoma is friable, or thromboembolic formed on the tumor surface. Embolic locations are mostly cerebral, revealed by ischemic stroke or retinal artery embolism responsible for sudden drop in visual acuity [10, 7]. Emboli can also affect the upper and lower extremities as well as the coronary arteries and cause myocardial infarction. In addition cardiac myxoma can generate general manifestations including fever, anemia, fatigue, joint pain, weight loss, and even cachexia and other systemic reactions [11]. Cardiac myxoma can also be discovered incidentally on cardiac or thoracic explorations carried out for another purpose. In our patients, two cases were revealed by ischemic stroke, one case by signs of heart failure and one case was discovered incidentally during routine transthoracic echocardiography during an episode of COVID19 infection. Transthoracic two-dimensional echocardiography gives the initial clue toward the presence of a cardiac mass, its location, echogenicity, morphology, measurements, mobility, its potential for embolization and the presence of a possible valvular obstruction. However, in some cases the diagnosis can be difficult, especially in patients with poor echogenicity. The delineation of left atrial tumor insertion site and tissue characteristics may be limited field using transthoracic echocardiography. Trans-esophageal echocardiography provides further details about the location as well as mobility, it offers a considerably better delineation of the tumor insertion site (commonly in the left atrial septum) and tissue characteristics especially for small-sized lesions [12]. It should be considered in any complicated case of cardiac mass [13]. Trans-esophageal echocardiography may also improve the detection of other major cardioembolic sources (e.g., intra-cardiac thrombus, vegetations or aortic arch plaque), as well as less common potential sources (e.g., patent foramen ovale, atrial septal aneurysm or left ventricular aneurysm) [14] and It can also show multiple cardiac locations of the tumor. In our second patient, transthoracic echocardiography showed a thickening of atrial septum, Trans-esopageal echocardiography performed for suspicion of a cardiac mass to better study the atrial septum and show the insertion of the mass on its left side.
5. Conclusion Cardiac myxomas are the most common primary cardiac benign tumors, that may cause a wide range of clinical symptoms not only such as cardiac disease, but also general manifestations. It is most frequently found in the left atrium, but others cardiac locations can be observed. Diagnosis is rarely made only on clinical findings, because there are no specific physical signs or symptoms. Two-dimensional transthoracic and trans-esophageal echocardiography, are the technique of choice for diagnosis and follow-up of this tumor. Surgery generally has good results and the anatomopathological study confirms the diagnosis of cardiac myxoma. Recurrence is possible, which makes periodic echocardiographic monitoring necessary after tumor resection.
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Hanane Mechal. Cardiac Myxoma: A Rare Case Series of 4 Patients and a Literature Review. Annals of Clinical and Medical Case Reports 2022