Giant right atrial myxoma complicated with massive pulmonary embolism and right-sided heart failure: a case report

Introduction

About 75% of myxomas occur in the left atrium and 10–20% in the right atrium (1). Giant right atrial myxoma is a benign neoplasm that arises from the endocardium and grows inside the right atrium into a mass of gelatinous appearance. It can lead to outflow obstruction tricuspid valve regurgitation and dislodge from the cardiac tissue, thus producing a wide range of potential symptoms and complications, from asymptomatic cases to serious presentations with acute pulmonary embolism (PE) or cardiogenic shock (2). There is limited data concerning optimal diagnostic and management strategies at present.

We present the case of a 43-year-old man admitted to our hospital with a 3-month history of progressive complaints of palpitations and fatigue, more recent worsening, and addition of symptoms such as palpitations and progressive dyspnea. The imaging revealed a giant right atrial myxoma occupying the right atrium. The patient was successfully resected with no recurrence, and his symptoms considerably improved. We present this case in accordance with the CARE reporting checklist (available at https://acr.amegroups.com/article/view/10.21037/acr-24-145/rc).

Case presentation

He was a 43-year-old male with no history of heart-related problems in the family. His occupation was that of a farmer, and for the last 8 months, he has experienced palpitations on and off that gradually became associated with breathlessness, became more progressive in the previous 10 days, were relieved by rest, and mainly precipitated by exertion, along with a nonproductive cough. He also gave a history of significant problems sleeping comfortably in a supine position, which usually made him sleep in an upright posture. Despite his symptoms, the patient had not sought medical attention elsewhere before presenting to our hospital. The patient is married and has no significant background other than that presented; he denied a familial history of related diseases. He attended high school and had no significant history of past medical conditions. He denied any history of alcohol abuse. But he is a smoker for the last 20 years at least and used to consume at least 10 sticks daily, never trying to stop it.

On physical examination, he had stigmata of right heart failure, including jugular venous distension, edema of the lower limbs, and hepatomegaly. A cardiac examination revealed a diastolic murmur at the left sternal border. He was in sinus rhythm, but right atrial enlargement was detected on an electrocardiogram.

Imaging studies, such as an admission echocardiogram, showed a sizeable mobile mass, measuring approximately 78 mm × 52 mm, in the right atrium (Figure 1A), which appeared to be originating at a distance from the interatrial septum. Around two-thirds of the myxoma mass in diastole is dragged by the blood through the tricuspid valve into the right ventricle, causing partial obstruction at the tricuspid orifice. In systole, it returns into the right atrium. Dilation of the inferior vena cava can also be appreciated, with an internal diameter of 24 mm. There may also be appreciable right ventricular dysfunction with signs of pulmonary artery hypertension.

Figure 1 Preoperative imaging of a giant right atrial myxoma. (A) Preoperative echocardiogram. (B) Preoperative enhanced CT scan. (C) Preoperative CTPA. CT, computed tomography; CTPA, computed tomography pulmonary angiography.

Preoperative levels of troponin I and myoglobin were within normal limits; however, the B-type natriuretic peptide (BNP) level was 1,890 ng/L. On the other hand, the D-dimer level was 494 ng/mL. No other significant abnormality was reflected by the preoperative results of different laboratory tests.

A coronary computed tomography angiography (CCTA) was also ordered to image the patient’s coronary status further, and he returned with multiple embolic occlusions involving the main left pulmonary artery, as well as segmental branches of the left lower lobe pulmonary artery. The patient underwent a computed tomography pulmonary angiography (CTPA). The CTPA revealed extensive, multifocal myxoma in the right atrium (Figure 1B) and myxomatous emboli in the main trunk of the left pulmonary artery and spreading out into its branches (Figure 1C). The diagnosis included: benign cardiac tumor (myxoma), PE affecting the main trunk of the left pulmonary artery, heart function New York Heart Association (NYHA) Class III, and bilateral minimal pleural effusions. Following a multidisciplinary discussion involving cardiologists, cardiothoracic surgeons, respiratory physicians, and anesthesiologists, it was determined that surgical intervention would likely benefit the patient.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). This research has been ethically approved by the Ethics Committee of the First Affiliated Hospital of Xinjiang Medical University (No. K202406-04; June 7, 2024). Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

The patient gave informed consent for the operation and demonstrated excellent cooperation throughout the process, who underwent an open-chest surgery to remove the giant right atrial myxoma, general anesthesia, cardiopulmonary bypass, and a right atriotomy were required to excise the giant right atrial myxoma. Upon exploration, a dark-red irregular lesion, looking like a piece of jelly, was seen as a sizeable gelatinous mass measured to be around 8 cm × 7 cm in situ (Figure 2A). The tumor was attached to the interatrial septum by a pedicle situated above the opening of the coronary sinus and eliminated the possibility of adequate tricuspid valve function. The tumor was excised completely (Figure 2B, due to the lack of intraoperative reference object photography for the tumor, please refer to Figure S1 for a reference object). Both the right and left atria, besides the ventricles, were carefully examined and were devoid of any pathology before closing the atrial septum. The patient’s temperature was allowed to drop to 29 ℃. Following the removal of the main trunk of the left pulmonary artery and its branches, the longitudinal incision opened segments of the tumor emboli in the arterial trunk. The tumor masses were excised, and a detailed re-exploration of the left pulmonary arterial trunk and its main branches revealed no residual embolism. Consequently, the incision in the left pulmonary artery was sutured closed.

Figure 2 Intraoperative findings of the giant right atrial myxoma. (A) Intraoperative view of the giant myxoma in the right atrium. (B) The resected giant myxoma, shown in a surgical bowl with an approximate diameter of 16 cm for scale (Figure S1).

Transesophageal echocardiography after the operation revealed a smooth and complete mass resection. No residual shunt was present, with normal heart function restored (Figure 3A). The patient was subsequently brought to the intensive care unit postoperatively for early recovery and further monitoring. Transfer to the cardiology ward for further observation and convalescent care was effected on the third postoperative day. Comprehensive postoperative management was instituted, including prophylactic medications to prevent infections, appropriate measures to manage coagulation, and therapies for an optimized fluid balance—all customized according to his specific needs. A postoperative CTPA showed no evidence of residual right atrial myxoma in the right atrium (Figure 3B) and PE in the pulmonary artery (Figure 3C), indicating the absence of embolic obstruction in the pulmonary arteries postoperatively. Histological examination (Figure 4) of the excised masses confirmed the diagnosis of myxoma; both the suitable atrial and left pulmonary artery tumors presented features compatible with myxomatous tissue. The patient’s clinical condition improved considerably, and he was discharged from the hospital on the 7th postoperative day. The patient underwent regular follow-up, which included routine echocardiography. In the 6-month follow-up, the patient reported excellent postoperative recovery with no recurrence of preoperative symptoms. Imaging studies showed no evidence of residual or recurrent tumors, no adverse or unanticipated events occurred throughout the treatment process. This case further reinstates the fact that giant right atrial myxomas with PE need to be managed by way of surgical excisions, which assure that complete tumor resections may be brought about with favorable results.

Figure 3 Postoperative imaging confirming the absence of tumor and pulmonary embolism. (A) Postoperative echocardiogram. (B) Postoperative enhanced CT scan. (C) Postoperative CTPA. CT, computed tomography; CTPA, computed tomography pulmonary angiography.

Figure 4 H&E histological image result consistent with atrial myxoma (×5). H&E, hematoxylin and eosin.

Discussion

Myxomas are the most common primary cardiac tumors (2,3), primarily affecting the left atrium, but they can also occur in the right atrium, as seen in our patient. The rarity of right atrial myxomas and their potential for embolization, as observed in our case, underscores the importance of prompt diagnosis and intervention. Notable risk factors of embolism for the cardiac myxoma patients include NYHA functional class I/II, an irregular tumor surface, hypertension, atypical tumor location, elevated fibrinogen levels, and a narrow base of the tumor, underscoring the importance of early surgical intervention in patients presenting with these characteristics to mitigate the risk of embolic events. Smoking is not a risk factor for embolism caused by cardiac myxomas (4). The patient’s symptoms, including exercise-aggravated palpitations and dyspnea, along with a notably high BNP concentration and the need for upright sleeping due to supine discomfort, illustrate the obstructive effect of the sizable right atrial myxoma on cardiac blood return. This cluster of symptoms is consistent with documented cases, highlighting how the tumor obstructs venous blood flow back to the heart, particularly affecting the cardiac filling process during diastolic venous return when supine, thus demonstrating a profound interference with the heart’s circulatory efficiency (5). The outcomes associated with giant right atrial myxoma causing massive embolization of the pulmonary artery can range from asymptomatic to life-threatening conditions, depending on factors such as the size and location of the tumor, the presence of comorbidities, and the timeliness of intervention (1,2). Early detection and intervention are crucial for improving patient outcomes and preventing life-threatening complications (1).

PE is a hazardous condition with serious hemodynamic consequences and needs timely treatment with the right therapy. About 50–70% of cases are due to deep vein thrombosis—most of these occur in the lower limbs (6). The mortality rate for PE in high-risk patients is 52.2% (7). Generally, the emboli are thrombi, and it is not common for emboli to arise from an atrial myxoma to the right atrium. PE is diagnosed through a clinical assessment combined with imaging studies and laboratory tests. Symptoms in the patient, history of the patient, and predisposing factors for PE, such as recent surgery, prolonged immobilization, or a previous history of deep venous thrombosis, should be considered first (8). In addition, tachypnea, tachycardia, and physical findings, which may include some of those suggestive of deep venous thrombosis, may help raise the suspicion of PE. Diagnostic imaging has replaced pulmonary angiography by interventional pulmonary as the historical gold standard. It is an invasive procedure with its risks, and since the advent of a much less invasive procedure, this historical gold standard has since been mostly abandoned. The most commonly used diagnostic method in current practice is CTPA (8). A multicountry, retrospective analysis found that the rate of CTPA for suspected PE cases from 2015 to 2019 in emergency departments had increased with more diagnoses of low-risk PEs and a trend toward outpatient management (9). Its benefits over ventilation-perfusion (V/Q) lung scan include greater availability, a lower rate of non-diagnostic results, and possible additional diagnoses if PE is not confirmed incidentally. The utility of CTPA in the determination and diagnosis of PE, by the identification of the embolus in the lumen of the pulmonary arteries, has been significantly helpful in the initiation of timely management (10). In our case, the overall picture, along with confirmation by the use of CTPA, led to a final diagnosis of PE, further reassured by intraoperative findings. Although CTPA is performed in most cases, other primary diagnostic tools are available for assessing patients with possible PE, including the V/Q lung scan, compression ultrasonography, and magnetic resonance imaging. Pulsed wave tissue Doppler imaging (PW-TDI) is significant in predicting the detachment of cardiac tumors. By measuring the increased peak antegrade velocity of the tumor, PW-TDI can assess the mobility characteristics of the tumor, thereby predicting the likelihood of its detachment. For patients with cardiac myxomas, we recommend to routinely perform PW-TDI to evaluate the risk of tumor detachment. Although surgical intervention is generally advised as soon as possible after the diagnosis of a myxoma, regardless of tumor size (11), there are still many asymptomatic patients at our medical center who refuse surgery, thereby increasing the risk associated with the tumor. Proper guidance based on the risk of myxoma embolization could significantly reduce the probability of adverse events related to myxomas.

This is a giant right atrial myxoma that is highly uncommon but, at the same time, very challenging because it has a high potential for causing severe symptoms along with severe consequences like pulmonary hypertension and embolism. When a cardiac myxoma in the right heart is detected, it is recommended to conduct further examinations to rule out the possibility of PE, in order to early diagnose whether PE is present. Similarly, for patients with PE, it is also recommended to rule out the possibility of a tumor in the right heart, because 10–30% of myxoma patients are asymptomatic (11) and PE can present as the primary symptom. There is limited information available regarding the growth rate of cardiac myxomas. According to previous studies, the growth rate of cardiac myxomas can vary from no growth to 1.36 cm/month in the maximal dimension (12-14). As the tumor grows larger, the risk related to obstruction and detachment may increase. Besides causing embolization due to detachment, Cardiac myxomas may obstruct intracardiac circulation, prolapse across valves (“ball-valve obstruction”), interfere with or damage (“ball destruction” effect) the valve structures, leading to regurgitation. cardiac myxomas can also directly invade the myocardium, resulting in impaired function or pericardial effusion (11). The earlier the diagnosis and intervention in preventing complications are initiated to reduce mortality rates, the better the chance of success of the surgical interventions. Cardiac surgeons carry out the delicate task of removal of the myxoma, at the same time trying to preserve the average performance and structure of the heart.

The profound hemodynamic disturbances with the potential for life-threatening complications underline the necessity for timely surgical treatment in patients with right atrial myxoma complicated by PE. Clinical suspicion of PE from the CCTA results was further established by the patient’s symptomatic presentation. Thus, CTPA was immediately ordered to confirm the diagnosis. The results then showed PE, most probably caused by the dislodged myxoma. Intraoperative findings of emboli in the main pulmonary artery, along with the giant myxoma, confirmed the potential for embolic complications. The findings in this case underscore the critical importance of prompt diagnosis, as delays can lead to significant morbidity and mortality. The study reported favorable outcomes at 6-month follow-up, but long-term follow-up remains necessary.

Conclusions

This case report only demonstrates that giant right atrial myxomas associated with PE need to be diagnosed early and treated immediately. It can, therefore, be concluded from the improvement of the patient after surgery and the absence of tumor recurrence at follow-up that an interdisciplinary approach guarantees good results for the patient in early detection and thorough care.

Acknowledgments

The writing of this research paper benefited from the application of artificial intelligence (AI) technologies, especially AI-assisted writing tools, for the polishing and refinement of the article.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://acr.amegroups.com/article/view/10.21037/acr-24-145/rc

Peer Review File: Available at https://acr.amegroups.com/article/view/10.21037/acr-24-145/prf

Funding: This work was supported by the “Tianshan Elite” High-Level Medical and Health Talent Cultivation Program (grant No. TSYC202301B004), and the National Natural Science Foundation of China (grant No. 82060907).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://acr.amegroups.com/article/view/10.21037/acr-24-145/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). This research has been ethically approved by the Ethics Committee of the First Affiliated Hospital of Xinjiang Medical University (No. K202406-04; June 7, 2024). Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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