Lymphoplasmacytic sclerosing pancreatitis is a rare entity that has been described under many different names and constitutes a diagnostic challenge as it may simulate a neoplastic process. Herein, we report a case of a 61-year-old woman who presented to our institution complaining of left flank pain and was found to have normal levels of amylase and lipase. An abdominal magnetic resonance image showed thickening of the pancreatic tail and compression of the pancreatic duct. The radiographic differential included both chronic pancreatitis and a neoplastic process. She underwent an exploratory laparotomy, during which a pancreatectomy and splenectomy were performed. Grossly, the pancreas contained a yellowish white, firm homogeneous mass measuring 6.5 x 3.3 x 2.9 cm involving the entire pancreatic tail and hilum of the spleen. Histologically, pancreatic sections showed extensive fibrosis admixed with an inflammatory infiltrate. This infiltrate was composed mainly of lymphocytes with multiple germinal centers, as well as plasma cells and eosinophils that surrounded pancreatic ducts and extended into the peripancreatic adipose tissue. No malignancy was identified, and the process was diagnosed as lymphoplasmacytic sclerosing pancreatitis.