There is no correlation between myxoma and pectus excavatum, as described in the literature, and the lack of relevant evidence reinforces the idea that these conditions are independent. It is observed that the conditions are distinct.
Primary cardiac tumors, although rare, have myxoma as the most common, with an approximate annual incidence of 0. 5 per million people. The origin of atrial myxoma is not completely established, but according to the current studies, myxomas arise from mesenchymal stem cells located in the subendocardial tissue near the fossa ovalis. Its etiology, in most cases, is sporadic, representing approximately 93% of all forms, and they frequently appear as isolated lesions in the left atrium in 75% to 85% of cases, with a low recurrence rate. Additionally, there is also a subgroup of familial myxomas associated with the Carney Complex, an autosomal dominant genetic syndrome (6, 7).
On the other hand, pectus excavatum also has several theories regarding its etiology, the most recognized being excessive growth of the costal cartilages, which displaces the sternum posteriorly, causing the chest depression. This anomalous process is not fully understood, but it is known that the ossification centers of the sternum and the histological structure of the costal cartilages show normal patterns (9). "Funnel chest" is a congenital condition, often isolated, but it can also be associated with genetic syndromes of connective tissue disorders, such as Marfan syndrome or Ehlers-Danlos syndrome, which may present with this thoracic abnormality (10). Usually this condition is asymptomatic; however the reduction in intrathoracic volume can lead to cardiac displacement, causing cardiopulmonary symptoms such as breathing difficulties, palpitations, and decreased daily exercise capacity (11)
Based on this information, it is observed that cardiac myxoma is not a typical manifestation of pectus excavatum, and the genetic syndromes of both conditions are unrelated. Therefore, it is clear that there is no connection between the etiological, cellular, or genetic mechanisms within the known pathophysiological processes, as myxoma and pectus excavatum occur in distinct ways.
Cardiac myxoma is a rare condition, with a prevalence of about 0. 03% in the general population. The annual incidence of cardiac myxoma ranges from 0. 05 to 0. 16 per 100, 000 people. In Japan, the incidence rate of cardiac myxoma has remained unchanged over the past 20 years, showing no significant variation during this period (12).
According to the literature, although no specific racial predisposition has been identified, the deformity is more common in individuals of Caucasian descent, and less common in Asians, African Americans, or Hispanics. The incidence of "funnel chest" can reach 8 cases per 1, 000 live births. However, the true incidence and prevalence of pectus excavatum are still not fully known and may be much higher than the currently recorded numbers (up to 5%, according to radiological reports), as large-scale population studies on the subject have not been conducted (10).
Therefore, since no studies have established a causal or associative relationship between myxoma and pectus excavatum, it is concluded that these conditions coexist rarely and without direct connection, reinforcing that their coincidence in an individual would be explained by chance, affecting them independently.
Cardiac Magnetic Resonance Imaging (CMRI) is essential for the accurate diagnosis of cardiac tumors, as it provides information on the heart's structure and hemodynamics. Additionally, it aids in surgical planning by determining the location, extent, and impact of lesions, allowing for a more effective therapeutic approach and a more positive prognosis. Moreover, it can generate detailed additional data on the heart's structure and hemodynamics, complementing the results of echocardiography. While echocardiography is commonly used as an initial test for identifying cardiac masses, it may be difficult to differentiate myxomas from other cardiac lesions, such as thrombi (13). CMRI functions as an essential non-invasive method for diagnosing primary cardiac tumors, offering images with better contrast resolution, a larger field of view, and the unique ability to distinguish lesions based on tissue characteristics. This exam also assists in determining the location, extent, and functional impact of the lesion. Currently, CMRI is the most reliable and accurate imaging technique, considered the "Gold Standard" for evaluating cardiac tumors, providing superior quality in terms of contrast resolution and tissue detail compared to other tests, such as transesophageal echocardiography. Thus, CMRI is essential for obtaining a conclusive diagnosis of cardiac masses, as well as determining therapeutic planning and patient prognosis. Large, benign tumors that cause symptoms are typically treated with complete surgical removal, and in most cases, individuals adapt satisfactorily to the surgical procedure. Patients with benign masses have a life expectancy comparable to the general population (14).
Currently, surgical removal of the atrial myxoma is the most recommended treatment, as there are no medications that can prevent tumor growth (6). Symptomatic myxomas need to be surgically removed as soon as possible after diagnosis, and the surgical approach should allow for minimal manipulation of the tumor, provide adequate access for complete lesion removal, including the pedicle area, allow assessment of all four heart chambers, and be both safe and effective. It is generally observed that the prognosis for cardiac myxoma surgery is very favorable, with mortality rates below 3% (5).
The patient's prolonged clinical course reflects the insidious progression of the atrial myxoma growth. Furthermore, the external calcification process and adhesions of the tumor to the left atrial wall support the extended evolution time of the condition before the patient sought medical assistance.
The choice of access to the thoracic cavity via right anterolateral thoracotomy was made due to both the pectus excavatum and the satisfactory access to the left atrium, the cardiac cavity of interest for tumor resection. The sternal reconstruction after a median sternotomy in a pectus excavatum patient might lead to a challenging and unique for the repair; the sternal adhesions and risk of cardiac injuries must be considered (15). In this case report, there was not the purpose of correction of pectus excavatum due to age, asymptomatic presentation and no patient’s desire.
