Multimodal cardiac imaging and endoscopic ultrasound-guided fine needle aspiration for accurate diagnosis and management of giant primary pericardial schwannoma: a case report with literature review

Ali Hakan Konuş^*

• Bingol State Hospital, Bingol, Türkiye

Background: Primary pericardial schwannoma is a highly unusual tumor, and only a few cases have been reported in the literature. We report a case of giant primary pericardial schwannoma that was accurately diagnosed and managed by multimodal cardiac imaging and transesophageal endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Case: A 47-year-old female patient presented with complaints of exertional dyspnea and non-anginal chest pain. The patient's New York Heart Association (NYHA) functional capacity score was 2-3 and N-terminus pro-B type natriuretic peptide (NT-proBNP) was elevated at 684 pg/ml. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) revealed a well-circumscribed mass containing a cystic lesion, compressing the left atrium (LA) and inferior vena cava (IVC). Thoracic computed tomography (CT) angiography revealed that the lesion was intrapericardial, located in the posterior mediastinum, 10.1x8.1x5.2 cm in size, had regular borders, and was compressing the esophagus. Magnetic resonance imaging (MRI) showed a well-circumscribed, T1-hypointense and T2-hyperintense pericardial mass. The mass was observed to have homogeneous signal intensity on T1 and T2-weighted images. CT and MRI showed that the mass did not cause myocardial involvement. Whole-body 18 F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)-CT images revealed that the mass was primary, had no metastasis, and had mild to moderate 18F-FDG avidity. Immunohistochemical evaluation with EUS-FNA determined the mass to be consistent with schwannoma, and the Ki-67 index was less than 1%. The mass was completely removed after the pericardium was opened by performing a median sternotomy approach. No residual mass was detected in the patient's follow-up. At 6-month and 1-year follow-ups, there were no symptoms, the NYHA score was 1, and NT-proBNP was normal. Conclusion: The integrative approach of multimodal cardiac imaging and EUS-FNA can effectively guide the surgical approach and management of primary pericardial schwannomas preoperatively. EUS-FNA may be an effective and safe method in the management of cardiac schwannomas. To our knowledge, this is the first case in which EUS-FNA has been used for the diagnosis of cardiac schwannoma.