title: Pancreatic cancer with a high serum IgG4 concentration.
abstract: Differentiation between autoimmune pancreatitis and pancreatic cancer is sometimes difficult. It has been reported that serum IgG4 concentrations are significantly elevated and particularly high (>135 mg/dL) in autoimmune pancreatitis. Measurement of serum IgG4 has become a useful tool for differentiating between autoimmune pancreatitis and pancreatic cancer. However, we present a 74-year-old female with a markedly elevated serum IgG4 (433 mg/dL) who underwent pancreaticoduodenectomy for pancreatic cancer. Elevated serum IgG4 levels continued after the resection. On histology, adenocarcinoma of the pancreas accompanied with moderate lymphoplasmacytic infiltration infiltrated the lower bile duct and duodenum, but there were no findings of autoimmune pancreatitis. Although a small metastasis was detected in one parapancreatic lymph node, regional lymph nodes were swollen. Abundant IgG4-positive plasma cells infiltrated the cancerous areas of the pancreas, but only a few IgG4-positive plasma cells were detected in the noncancerous areas. Pancreatic cancer cells were not immunoreactive for IgG4. An abundant infiltration of IgG4-positive plasma cells was detected in the swollen regional lymph nodes and in the duodenal mucosa. We believe that the serum IgG4 level was elevated in this patient with pancreatic cancer as the result of an IgG4-related systemic disease that had no clinical manifestations other than lymphadenopathy.
authors.affiliation: Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bukyo-ku, Tokyo, Japan. kamisawa@cick.jp
authors.forename: Terumi
authors.initials: T
authors.lastname: Kamisawa
authors.forename: Pong-Yui
authors.initials: PY
authors.lastname: Chen
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Tu
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Naoto
authors.initials: N
authors.lastname: Egawa
authors.forename: Kouji
authors.initials: K
authors.lastname: Tsuruta
authors.forename: Atsutake
authors.initials: A
authors.lastname: Okamoto
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Hishima
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000175:diagnosis; D000368:Aged; D001327:Autoimmune Diseases / Q000175:diagnosis; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D010195:Pancreatitis / Q000175:diagnosis
chemical_list: D007074:Immunoglobulin G