Endosonography-Guided Biopsy of Mediastinal and Pancreatic Tumors

Abstract

Although endoscopic ultrasound (EUS) allows sensitive imaging of the upper gastrointestinal (GI) tract, it remains difficult to differentiate between benign and malignant lesions on the basis of ultrasound morphology. The purpose of this study was to determine the value of EUS-guided biopsy for the diagnosis of submucosal and extraluminal tumors. EUS-guided biopsy was carried out in 50 patients with upper GI-tract lesions. All patients were examined using a flexible echoendoscope with a 5/7.5 MHz curved array transducer. A specially designed biopsy device (type Vilmann) with a fine needle (diameter 0.8 mm) was used for EUS-guided biopsy. EUS-guided biopsy was performed for evaluation of mediastinal lesions (n = 15), pancreatic tumors (n = 26) and submucosal (n = 5) or stenotic tumors of the esophagus (n = 4). Fine-needle aspiration yielded diagnostic tissue samples in 44 of 50 patients (88%). Histology demonstrated benign lesions in 20 of 44 patients and malignant tumors in the other 24 patients. EUS-guided biopsy failed in only six patients (12%): in four patients it was impossible to advance the needle into very hard pancreatic tumors; non-representative biopsy material was obtained in two further cases. The results of EUS-guided biopsy were validated by surgery (n = 21), autopsy (n = 3) or clinical follow-up (n = 20). After a mean follow-up of 16 months there is no evidence of malignancy in any of the patients with benign histology. The sensitivity and specificity of EUS-guided biopsy in the diagnosis of malignancy were 88% and 100%, respectively. None of the patients experienced complications related to endosonographic biopsy. EUS-guided biopsy with the Vilmann needle device is a safe and accurate method for tissue sampling of extraluminal lesions. This technique considerably improves the diagnostic value of endosonography.