Endosonographically guided transduodenal and transgastral fine-needle aspiration puncture of focal pancreatic lesions.

Mass lesions of the pancreas can be clearly visualized by endoscopic ultrasonography. For the differentiation of benign from malignant mass lesions, however, cytological examination is still recommended. As transcutaneous fine-needle biopsies have a limited diagnostic value, we have evaluated the efficiency of transmural (trangastral, transduodenal) endosonographically guided fine-needle aspiration (EUS-guided FNA) puncture for cytological confirmation of such pancreatic mass lesions. EUS-guided FNA puncture was performed in 11 patients with focal pancreatic solid lesions. In 4 patients a malignant mass lesion and in 2 patients a benign lesion were correctly identified by EUS-guided FNA puncture, while in 4 patients a false benign diagnosis was established and in 1 patient with a malignant mass lesion a sufficient cytological sample could not be obtained. Histological confirmation or rejection of the cytological diagnosis gained by EUS-guided FNA puncture was obtained in all patients by surgical biopsy or resection. It is concluded that transmural EUS-guided FNA puncture-with the application of a curved-array EUS transducer scanning parallel to the axis of the endoscope-is a new approach to the cytological diagnosis of pancreatic mass lesions. However, the of flexible puncture needles with a short needle tip-destined for multiple use-results in a considerable amount of false-negative diagnoses, as the needle tip frequently can only be advanced into the margin of the lesion. New prototypes of aspiration needles with an extending steel are presently under study for improved transmural EUS-guided FNA puncture.