Benign Epithelial Inclusions in Peripancreatic Lymph Nodes

Benign epithelial inclusions are rarely found in peripancreatic lymph nodes and have not been studied by up-to-date immunohistochemistry. Here, we describe 2 cases of benign epithelial inclusions in the peripancreatic lymph nodes with discussion of differential diagnosis. The first case was a 2.2 cm lymph node from a 61-year-old woman with pancreatic ductal adenocarcinoma. The second case was a 4.3 cm lymph node from a 28-year-old man with distal common bile duct cholangiocarcioma. The epithelial inclusions in the first case consisted of several small squamous cell nests with central duct-like lumina. The lymph node from the second case showed convoluted cystic inclusions lined by a single layer of bland cuboidal epithelium with scattered mucin-producing cells. We also conducted literature review on similar lesions and found that some lesions were associated with pancreatic hetertopia. It is imperative in clinical practice to distinguish these epithelial inclusions in the lymph nodes from tumor metastasis. A hypothetic connection of these benign epithelial inclusions in the peripancreatic lymph nodes to the enigmatic pancreatic lymphoepithelial cysts is suggested.