Localized lymphoid hyperplasia (pseudolymphoma) of the pancreas presenting with obstructive jaundice

A case of hyperplastic lymphoid lesion of the pancreatic head manifested by obstructive jaundice is presented. A 57-year-old woman who complained of malaise and icterus underwent pancreatoduodenectomy under the clinical diagnosis of pancreatic carcinoma. The lesion was diagnosed as localized lymphoid hyperplasia (pseudolymphoma) based on the presence of hyperplastic follicles with germinal center and mixed infiltration of plasma cells and mature lymphocytes with no significant cytologic atypia. The immunostaining revealed polyclonal origin of the lymphoplasmocytic component. Localized lymphoid hyperplasia occurs in a wide variety of sites; however, to our knowledge, its occurrence in the pancreas has not been documented previously.