Endoscopic ultrasonography-guided fine-needle aspiration biopsy of lymph nodes

The recent introduction of convex linear array echoendoscopes equipped with a biopsy channel has made fine-needle aspiration biopsy (FNAB) under direct endosonographic guidance possible. Because the imaging and instrumentation planes overlap, the operator can visualize a biopsy needle lengthwise as it enters the sector-shaped sound field. We performed EUS-guided FNAB of lymph nodes in seven patients who met the following criteria: (1) Lymph node size over > 1 cm; (2) no endoscopic or endosonographic evidence for tumor involvement of bowel wall interposed between the lymph node and the transducer; and (3) absence of coagulopathy or thrombocytopenia. A positive tissue yield was obtained in six patients, of whom five had malignant cells identified on cytology. The patient with an inadequate yield had a dry aspirate, possibly related to prior irradiation treatment for esophageal carcinoma. No procedure-related complications were observed. We conclude that EUS-guided FNAB of lymph nodes is technically feasible, provides a high diagnostic yield, and appears to be safe. Further studies to determine the sensitivity and specificity of this novel procedure are warranted.