Asymptomatic Pericardial Cyst: A Case Report and Brief Review of its Management

A 59-year-old female patient, with high blood pressure, diabetes mellitus , and dyslipidemia, was referred to a tertiary care service for investigation of an irritating, non-productive cough that had onset two months prior. She denied symptoms of reflux or postprandial stuffiness, as well as nasal congestion or signs of allergic rhinitis. She denied smoking, alcohol consumption, and contact with individuals with tuberculosis and did not report previous pneumonic events. She was taking losartan (50mg 12/12h), atenolol (25mg 12/12h), metformin (850mg 2x/day), and simvastatin (20mg at night), in addition to 100mg of acetylsalicylic acid at lunch daily. She was initially medicated with dexchlorpheniramine maleate 2 mg per day and additional biochemical tests and a simple chest x-ray were requested. Upon return, she reported complete improvement in respiratory symptoms, biochemical tests were within normal limits, but the x-ray revealed a mass in the right anterior region of the chest (Figure 1A), which began to be investigated.


Asymptomatic Pericardial Cyst: A Case Report and Brief Review of its Management
Matheus Rodrigues Barbosa, 1 Henrique Turin Moreira, 1 Gustavo Jardim Volpe, 1 Danilo Tadao Wada, 1 Minna Moreira Dias Romano, 1 Andre Schmidt 1 Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, 1 Ribeirão Preto, SP -Brazil A 59-year-old female patient, with high blood pressure, diabetes mellitus, and dyslipidemia, was referred to a tertiary care service for investigation of an irritating, non-productive cough that had onset two months prior.She denied symptoms of reflux or postprandial stuffiness, as well as nasal congestion or signs of allergic rhinitis.She denied smoking, alcohol consumption, and contact with individuals with tuberculosis and did not report previous pneumonic events.She was taking losartan (50mg 12/12h), atenolol (25mg 12/12h), metformin (850mg 2x/day), and simvastatin (20mg at night), in addition to 100mg of acetylsalicylic acid at lunch daily.
She was initially medicated with dexchlorpheniramine maleate 2 mg per day and additional biochemical tests and a simple chest x-ray were requested.Upon return, she reported complete improvement in respiratory symptoms, biochemical tests were within normal limits, but the x-ray revealed a mass in the right anterior region of the chest (Figure 1A), which began to be investigated.
Given the suspicion of a cyst or neoplasia, a chest computed tomography was requested, which revealed a cystic lesion with regular contours located in the right cardiodiaphragmatic sinus, in contact with the pericardial surface on the right (Figure 3A).
Upon consultation with cardiology, the patient was asymptomatic and had no abnormalities on clinical examination, and it was found that the comorbidities were under adequate laboratory control.An electrocardiogram and a transthoracic echocardiogram were then requested, with only the latter being performed, which revealed cavities with preserved dimensions and systolic function, but with a hypoechogenic image in the right atrioventricular sulcus of imprecise dimensions, apparently without causing cardiac compression (FIGURE 2).A review of old medical records indicated that a chest x-ray taken 10 years earlier showed a mass with the same topography and smaller dimensions (Figure 1B).A magnetic resonance imaging (MRI) examination of the heart was then requested, which revealed the presence of a pericardial cyst, located in the anterior mediastinum, measuring 8.8 x 3.6 x 7.4 cm (Figure 3B).No significant changes were observed in the cardiac chambers and in the functions of the left and right ventricles.The patient remains under semi-annual clinical follow-up, without symptoms, for a period of one year, under expectant management.

Discussion
Pericardial cyst is an uncommon clinical entity, with an estimated incidence of 1/100,000 to 1/10,000 autopsies.Its etiology is not yet completely understood, but it is believed to be due to an abnormal development of the pericardium during embryogenesis.It is necessary to differentiate the cyst from the pericardial diverticulum, which possibly have the same origin but, in the latter, there is communication with the pericardial cavity. 1 Most cases are asymptomatic, even with large dimensions, and the lesion is often discovered incidentally during imaging exams or heart surgery.When symptomatic, the clinical presentation is variable and may include cardiorespiratory symptoms, such as chest pain, dyspnea, 2 cough, 3 sudden cardiac death or signs of cardiac tamponade. 4e diagnosis of pericardial cyst is initially suspected by the incidental performance of a chest x-ray, which shows the mass attached to the cardiac silhouette.Doppler echocardiography, computed tomography and cardiac MRI allow the diagnosis to be confirmed, notably the last two. 5Chest x-ray may reveal a mediastinal mass or an area of increased density.Computed tomography (CT) scans and cardiac MRIs provide more detailed information about the location, size, and characteristics of the cyst.Transthoracic echocardiography can be useful in evaluating cardiac function and the presence of cyst-related complications, such as cardiac compression.Differential diagnosis should include neoplasms and, more rarely, migratory hydatid cysts, which may be single. 6e approach to managing a pericardial cyst depends on presence or absence of symptoms, size of the cyst, impairment of cardiac function, and presence of complications, notably rupture and hemorrhage.In asymptomatic patients, an expectant approach with regular follow-up every one or two years is a safe and effective option, avoiding unnecessary invasive procedures.Recent data suggest that, in most cases, size may be maintained or even reduced, contrary to what was evidenced in this case. 7rgical intervention is reserved for symptomatic patients or when there are significant complications such as cardiac compression or tamponade.Although open surgery is the most commonly used approach, punctures for drainage and relief and alcohol-based sclerosis thoracoscopy have been used. 8

Conclusion
Pericardial cyst is a rare condition that can be asymptomatic and diagnosed incidentally.Expectant management is a valid option in asymptomatic cases, with regular monitoring to detect the development of symptoms or complications.Surgical intervention must be based on an individualized assessment, considering the presence of symptoms, the size and location of the cyst, cardiac function, and the risk of complications.It is paramount to increase awareness of this clinical condition to ensure proper diagnosis and management of patients.Additional studies are needed to improve our understanding of the etiology, pathophysiology, and treatment approaches of pericardial cyst.