EUS-guided fine needle biopsy: minimally invasive access to metastatic or recurrent cancer

Endoscopic ultrasound (EUS) is a sensitive technique for preoperative staging of gastrointestinal tumors. However, the value of this technique in the diagnosis of metastatic or recurrent disease is limited by the inability to differentiate malignant and benign lesions. We have prospectively investigated the role of EUS-guided biopsy in the evaluation of peri-intestinal tumors.

EUS-guided biopsy was performed in 167 patients with thoracic, intra-abdominal or pelvic lesions. The upper gastrointestinal tract was examined with a flexible echoendoscope equipped with a 7.5 MHz curved array transducer. For transrectal EUS a rigid endoprobe with a bifocal multiplane transducer (10 MHz) was used. Both instruments allowed to observe the biopsy procedure exactly in the longitudinal scan plane.

Real time ultrasonography guidance of the biopsy needle enabled precise tissue sampling even of small lesions with a diameter of 1 cm. Overall EUS-guided fine needle biopsy yielded tissue samples for histopathologic or cytologic analysis in of 151 of 167 patients. Histology demonstrated benign lesions in 71 of 74 patients and malignant tumors in 68 of 93 patients. EUS-guided fine needle biopsy failed to provide the correct diagnosis in 28 cases. The overall sensitivity and specificity of EUS-guided biopsy in the diagnosis of malignancy were 73 and 96%, respectively. The histopathological results changed the clinical and endosonographic diagnosis in 49 patients. No complications were observed related to the biopsy.

EUS-guided needle biopsy is a safe and efficient method for tissue sampling of peri-intestinal lesions. This minimally invasive technique provides adequate biopsies and improves the diagnostic value of endoscopic ultrasonography considerably.