Endoscopic ultrasound-guided fine needle aspiration of the celiac ganglion: A diagnostic pitfall

Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) is now widely used as a primary tool in the evaluation of lymphadenopathy in both the mediastinum and abdomen. A sympathetic ganglion may be mistaken for an enlarged lymph node on endoscopic ultrasound and are rarely sampled as such. A 51-year-old female presented with a history of weight loss, vomiting for several months, and right upper quadrant discomfort. Computed tomography (CT) and magnetic resonance imaging (MRI) scans showed a dilated common bile duct (CBD) with a possible periampullary mass, paraaortic, and pericelial lymph nodes suspicious for metastatic disease. Endosonography revealed a 17 mm oval hypoechoic structure with distinct margins in the para-aortic, celiac axis region suggestive of an enlarged lymph node. An EUS-FNA was done. Cytology revealed ganglion cells with large oval epithelial-like cells with round nuclei and prominent nucleoli consistent with a benign sympathetic ganglion. It is crucial for the cytopathologist to be aware of the fact that the endoscopist might have sampled a celiac ganglion instead of a celiac lymph node and be able to distinguish the cytological features of a benign sympathetic ganglion from a malignant process.