A case of pancreatic cancer with formation of a mass mimicking alcoholic or autoimmune pancreatitis in a young man. Possibility of diagnosis by hypermethylation of pure pancreatic juice.
BACKGROUND
Mass-forming pancreatitis can be divided into two distinct types: alcoholic and autoimmune. There have been some cases of an ambiguous diagnosis although care was taken to differentiate between alcoholic mass-forming pancreatitis, focal type autoimmune pancreatitis and pancreatic cancer.


METHODS
We report a case of pancreatic cancer mimicking alcoholic or autoimmune pancreatitis with the formation of a mass in a 32-year-old man with a history of heavy drinking. Although both serum immunoglobulin G and immunoglobulin G4 levels were normal, many serum auto-antibodies, including the antinuclear antibody, were detected. After he stopped drinking, abdominal computed tomography showed a pancreatic head mass 28 mm in diameter with little and weak enhancement in the early and delayed phases, respectively. Endoscopic retrograde cholangiopancreatography showed an obstruction of the main pancreatic duct in the pancreatic head and marked stenosis of the lower common bile duct. Although a percutaneous ultrasound-guided pancreatic biopsy demonstrated no evidence of autoimmune pancreatitis, he was treated with prednisolone to test the efficacy of steroid therapy. However, the pancreatic mass became enlarged after steroid therapy, and he underwent surgery during which the mass was found to be pancreatic cancer. Although the patient was treated with gemcitabine, he died 5 months after surgery. We retrospectively assessed DNA hypermethylation in the patient's pure pancreatic juice obtained on admission. We observed hypermethylation of the cancer-specific gene tissue factor pathway inhibitor 2 (TFPI2).


CONCLUSIONS
This finding suggests that if the DNA hypermethylation of pure pancreatic juice had been assayed before steroid therapy, it would have supported the diagnosis of pancreatic cancer, and steroid therapy could have been avoided.
Ohtsubo
Koushiro
K
Department of Internal Medicine and Medical Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan. ohtsubo@kenroku.kanazawa-u.ac.jp
Watanabe
Hiroyuki
H
Okada
Gensaku
G
Tsuchiyama
Tomoya
T
Mouri
Hisatsugu
H
Yamaguchi
Yasushi
Y
Motoo
Yoshiharu
Y
Okai
Takashi
T
Amaya
Koji
K
Kitagawa
Hirohisa
H
Ohta
Tetsuo
T
Gabata
Toshifumi
T
Matsuda
Koichiro
K
Ohta
Hideki
H
Sawabu
Norio
N
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D000328:Adult; D001327:Autoimmune Diseases / Q000175:diagnosis*; D001706:Biopsy; D002760:Cholangiopancreatography, Endoscopic Retrograde; D019175:DNA Methylation; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006023:Glycoproteins / Q000235:genetics; D006801:Humans; D008297:Male; D010189:Pancreatic Juice / Q000502:physiology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D019512:Pancreatitis, Alcoholic / Q000175:diagnosis*; D014463:Ultrasonography
D006023:Glycoproteins; C021240:tissue-factor-pathway inhibitor 2