Superior vena cava syndrome: diagnosis of etiology with EUS-guided FNA

Abstract

Superior vena cava syndrome (SVCS) is the clinical manifestation that results from compression or occlusion of the superior vena cava and thus impairs the return of venous blood from the head, neck, and upper extremities. Lung cancer is the leading cause of SVCS, followed by non-Hodgkin’s lymphoma, and then metastatic disease, in particular, breast and prostate cancer. Because of the many therapeutic advances in the treatment of lung cancer, lymphoproliferative disorders, and other malignant etiologies of SVCS, the current management stresses the importance of an accurate histologic diagnosis of the underlying etiology before treatment. A histologic diagnosis can sometimes be obtained by bronchoscopy, lymph-node biopsy, or transvenous biopsy. Unfortunately, the diagnostic yield for these studies is often low. Previous studies showed that, when these less-invasive techniques failed, cervical mediastinoscopy or anterior mediastinotomy is more often successful in obtaining tissue diagnosis in SVCS. The sensitivity and specificity of cervical mediastinoscopy and anterior mediastinotomy in detecting the etiology with SVCS has been reported at 97.4% and 100%, respectively, with a diagnostic accuracy of 97.4%. However, because these techniques involve the dissection and biopsy of tissue in the presence of distended neck veins and collateral circulation, they entail the risk of hemorrhage and other complications. One review article reported the overall morbidity associated with these more-invasive procedures at 8.2%. To the best of our knowledge, none of the previously published reports included establishing the etiology of SVCS by EUS-guided FNA (EUS-FNA). EUS-FNA was successfully used in the diagnosis of malignant lymph nodes associated with GI and pulmonary malignancies. The overall accuracy of EUS-FNA in detecting the diagnosis of malignancy was reported at 86%, with a sensitivity of 84% and a specificity of 96%. EUS-FNA can safely, reliably, and accurately obtain tissue specimens adequate for cytologic diagnoses, eliminating the need for more-invasive methods or surgical intervention. With regard to its sensitivity, specificity, and overall accuracy, EUS-FNA is comparable with cervical mediastinoscopy or anterior mediastinotomy. Yet, as a relatively less-invasive technique, EUS-FNA might have a niche in diagnosing the etiology of SVCS. Two cases of SVCS are reported here, in which EUS-FNA established