JOP. J Pancreas (Online) 2004; 5(6):527-530. JOP. Journal of the Pancreas – http://www.joplink.net – Vol. 5, No. 6 – November 2004. [ISSN 1590-8577] 527 CLINICAL IMAGING Autoimmune Pancreatitis. A Case Mimicking Carcinoma Raffaele Pezzilli 1 , Riccardo Casadei 2 , Lucia Calculli 3 , Donatella Santini 4 Departments of 1 Internal Medicine, 2 Surgery, 3 Radiology, and 4 Pathology, Sant'Orsola-Malpighi Hospital. Bologna, Italy Autoimmune pancreatitis is a rare but fascinating type of chronic pancreatitis and an increasing number of cases are being reported from Japan and Europe [1]. Patients with autoimmune pancreatitis rarely complain of the typical severe abdominal pain of pancreatitis and usually arrive at the hospital due to painless jaundice [2]; other symptoms of autoimmune pancreatitis include non- specific mild abdominal pain and weight loss. There is no laboratory hallmark of the disease, even if cholestatic profiles of liver dysfunction with only mild elevations of amylase and lipase levels have been reported [3]. We report a case which was suspected of being pancreatic cancer but which revealed histologic evidence of autoimmune pancreatitis. A 68-year old male was admitted to our Department because of asthenia and weight loss (about 8 kg in 2 months). He was a light drinker (he started to drink 40 g of pure alcohol per day at the age of 18 years) and a heavy smoker (he started to smoke 30 cigarettes per day at the age of 18 years). At the age of 45, he underwent a left colectomy for the perforation of a diverticulum; at the age of 48, he was found to be affected by arterial hypertension and was treated with ACE-inhibitors and beta-blockers); finally, at the age of 53, he was operated on for carcinoma of the prostate. He underwent a colonoscopy one month before admission which showed colonic diverticula of the right and transverse colon. On admission, physical examination was unremarkable. The laboratory examination revealed normal values of white blood cell count, hemoglobin, mean cellular volume, hematocrit, and platelet count. The renal and hepatic functions were also normal. Plasma glucose was 2.12 g/L (reference range: 0.60-1.10 g/L), plasma C- peptide 0.8 ng/mL (reference range: 0.8-3.9 ng/mL), glycosylated A1 hemoglobin was 10% (reference range: 4.3-5.9%). Serum amylase was normal and pancreatic isoamylase slightly abnormal (117 U/L, reference range: 17-115 U/L). The serum carcinoembryonic antigen was normal, whereas serum CA 19-9 was 97 U/mL (reference range: 0-37 U/mL). Non-organ and organ specific autoantibodies were negative, and there was no hypergammaglobulinemia or elevated levels of serum IgG. An abdominal ultrasonography showed a hypoechogenic mass having a diameter of 24x19 mm Image 1