Intravascular EBUS-TBNA for Diagnosis of Primary Mediastinal Seminoma Invading the Superior Vena Cava: A Case Report

Background Mediastinal seminoma is a very rare extragonadal malignant germ cell tumor often misdiagnosed. Case presentation: A 27-year-old male presented with dyspnea. Imaging exhibited a mass invading the right upper lobe and extending to the anterior mediastinum and invading the superior vena cava (SVC). CT-guided biopsy showed necrotizing granulomas, and empiric antituberculosis therapy was initiated. The absence of clinical and radiological improvement after four months necessitated re-evaluation via EBUS-TBNA to reassess the diagnosis. EBUS-TBNA from the mass invading SVC through intravascular approach was performed without significant adverse events and yielded adequate tissue, with rapid on-site assessment and histopathology confirmed seminoma. Conclusions Intravascular EBUS-TBNA is a safe, minimally invasive technique for diagnosing primary mediastinal Seminoma invading the SVC.