Surgery in autoimmune pancreatitis

Introduction: Autoimmune pancreatitis (AIP) is a disease that may mimic malignant pancreatic lesions both in terms of symptomatology and imaging appearance. The aim of the present study is to analyse experiences of surgery in patients with AIP in one of the largest European cohorts. Methods: We performed a single-centre retrospective study of patients diagnosed with AIP at the Department of Abdominal Diseases at Karolinska University Hospital in Stockholm, Sweden, between January 2001 and October 2020. Results: There were 159 patients diagnosed with AIP, and among them 35 (22.0%) patients had surgery: 20 (57.1%) males and 15 (42.9%) females; average age at surgery was 59 years (range 37-81). Follow-up period after surgery was 67 months (range 1-235). AIP type 1 was diagnosed in 28 (80%) patients and AIP type 2 in 7 (20%) patients. Malignant and premalignant lesions were diagnosed in 8 (22.9%) patients for whom AIP was not the primary differential diagnosis but, in all cases, it was described as a simultaneous finding and recorded in retrospective analysis in histological reports of surgical specimens. Conclusions: Diagnosis of AIP is not always straightforward, and, in some cases, it is not easy to differentiate it from the malignancy. Surgery is generally not indicated for AIP but might be considered in patients when suspicion of malignant/premalignant lesions cannot be excluded after complete diagnostic work-up.

Case Report: Development of Type 1 Autoimmune Pancreatitis in an Adolescent With Ulcerative Colitis Mimicking Pancreatic Cancer

Introduction: Autoimmune pancreatitis (AIP) is a rare extraintestinal manifestation of inflammatory bowel disease (IBD) which is typically responsive to corticosteroid treatment.Case Presentation: We report a case of a 17-year-old male diagnosed with ulcerative colitis who subsequently developed acute pancreatitis. Blood tests demonstrated elevated pancreatic enzyme levels of amylase (1319 U/L) and lipase (809 U/L). Abdominal computed tomography revealed peripancreatic fat stranding and the presence of a perisplenic pseudocyst. Azathioprine and mesalazine were stopped as possible causes of drug-induced pancreatitis. However, pancreatic enzymes remained elevated and corticosteroid treatment was started. Despite corticosteroid therapy, amylase and lipase levels continued to increase. Infliximab was started due to a flare in gastrointestinal symptoms of ulcerative colitis. Follow-up abdominal ultrasonography revealed a pancreatic tail mass. Tumor markers, including CA 19-9, were elevated and atypical cells were seen on histological examination of an endoscopic ultrasonography-guided fine needle aspiration biopsy. Surgical pancreaticosplenectomy was performed for suspected pancreatic neoplasm. Surprisingly, histology revealed chronic pancreatitis with storiform fibrosis and infiltration of IgG4-positive cells, compatible with AIP type 1. Thereafter, pancreatic enzymes gradually decreased to normal levels and the patient has been in remission for 9 months on infliximab monotherapy.Conclusion: Pediatric gastroenterologists should keep in mind that AIP may develop during the natural course of pediatric IBD. Moreover, the development of pancreatic fibrosis may be non-responsive to corticosteroid treatment and mimic pancreatic neoplasia.

Focal IgG4-related autoimmune pancreatitis with distal choledochal adenocarcinoma: a rare case report

Background Autoimmune pancreatitis (AIP) is a rare disease that manifests as pancreatic involvement in systemic IgG4-related disease (IgG4-RD), a special type of chronic pancreatitis caused by autoimmune abnormalities. The main imaging manifestations of IgG4-related AIP consist of diffuse or localized pancreatic enlargement and irregular pancreatic duct narrowing. The diagnosis of AIP is challenging because it can present with focal lesions, similar to radiologically bile duct cancer or pancreatic cancer. Case presentation A 55-year-old male patient was admitted with painless jaundice and multiple radiographic findings of pancreatic head mass, as well as intrahepatic and extrahepatic bile duct dilatation. Various imaging methods indicated pancreatic cancer. However, the endoscopic ultrasonography guided fine needle aspiration (EUS-FNA) and a laparoscopic pancreatic biopsy suggested an IgG4-related AIP. After one month, magnetic resonance imaging showed that the lesion had slightly grown. Combined with CA19-9 and other indexes, the possibility of malignancy was high and there were still surgical indications. The pathological analysis following a pancreaticoduodenectomy revealed poorly differentiated adenocarcinoma in the distal common bile duct. Conclusion To date, few reports have described pancreatic or extrapancreatic malignancies in AIP patients, and no association between AIP and bile duct adenocarcinoma has been previously confirmed. This case discuss the differentiation between AIP and malignancy, recent research progress, and the correlation between the two diseases, highlights the importance of carefully evaluating patients with AIP to rule out potential tumors, as well as the critical need for follow up treatment.