Can the EUS Nodal Assessment Predict the Cytopathological Type of Pancreatic Tumors?

Abstract

Background: Different pancreatic tumor cell types include ductal adenocarcinomas (85-90%), acinar cell carcinomas, and islet cell carcinomas. Pancreatic neoplasms other than adenocarcinoma may have different patterns of metastatic spread. Aim: To determine whether the presence of, size and number of lymph nodes on EUS, in patients with a pancreatic neoplasm were predictive of the cell type. Methods: We retrospectively reviewed 233 patients from our EUS data base (from 1/97-8/03) who were diagnosed with pancreatic neoplasm by EUS-guided FNA who had undergone complete EUS TNM staging. We analyzed EUS nodal information of 2 subgroups, those with adenocarcinoma (A) and those without (B). A (n=219): adenocarcinoma (n=205), mucinous cystadenocarcinoma (n=11) and adenosquamous carcinoma (n=3). B (n=14): neuroendocrine tumors (n=9), lymphoma (n=2), acinar cell (n=1), plasmacytoma (n=1) and anaplastic (n=1). Of the 233 patients, 119 patients (51%) had lymph nodes seen on EUS. Of these, 60 patients had EUS-guided FNA of the lymph nodes. When FNA was not done, 24/59 patients were classified as N1 based on size ≥1cm. Results: EUS stage N1 and lymph nodes with size ≥ 2cm were predictive of cell types other than adenocarcinoma (Table 1). When the 59 patients (all in group A) who had lymph nodes seen on EUS but without FNA were excluded, similar results were found (Table 2). Conclusion: The presence of lymph nodes and lymph node size ≥ 2cm on seen EUS in the diagnosis and staging of pancreatic neoplasm were predictive a cell type other than adenocarcinoma. This information may guide the endosonographer with procedural strategies and index of suspicion for the less frequently seen pancreatic neoplastic cell types, during the EUS examination.