Differential Diagnosis of Enlarged Periportal Lymph Nodes in Patients Without Pancreatobiliary Malignancies

      Introduction: Enlarged periportal lymph nodes are frequently visualized during imaging of the upper abdomen. Periportal nodes are frequently enlarged in patients with cancers of the liver, gallbladder, biliary tree and pancreas and lymphoma and their identification is essential step in staging and treatment planning of these cancers. However there is no published data on the significance and differential diagnosis of enlarged periportal lymph nodes in patients without above-mentioned cancers. Methods: We searched our database of patients who 1) underwent endoscopic ultrasound for evaluation of enlarged periportal lymph nodes or 2) were found to have enlarged periportal lymph nodes during EUS examination. Patients with identifiable pancreatic, biliary, gallbladder or liver cancers were excluded. Periportal lymph nodes were considered enlarged if they were ≥10 mm in diameter. FNA of one or more nodes was performed. Immediate assessment of FNA aspirates was done by cytologists after the smears were stained with Diff-quik and Papanicoulou method. FNA specimens were collected for immunostaining and flow cytometry whenever indicated. Results: Forty-one patients with enlarged periportal lymph nodes qualified for inclusion in this study. Lymph node size ranged from 10-35 mm. Thirteen patients had ≤3 enlarged periportal nodes. Concomitantly enlargement was seen in peri-pancreatic nodes (n = 9), celiac (n = 5) and mediastinal group (n = 4). Six of the 41 patients were found to have malignancy in the periportal lymph nodes. Three of these patients had past history of cancer-malignant melanoma, colon cancer and appendiceal cancer. Two of remaining three patients had metastatic adenocarcinoma from unknown primary and the third patient had metastatic liver cancer in periportal LN that was not identified prior to EUS-FNA. Granulomas were seen in three patients (including one patient with HIV) and lipogranulomatosis was seen in another three patients who also had biliary strictures. All other lymph nodes had mixed lymphocyte population. Conclusions: A small but significant number of patients with enlarged periportal lymph nodes in patients with identifiable pancreatobiliary and liver cancers harbor malignancy. We recommend that these nodes should be sampled with FNA at the time of EUS examination.