Follicular pancreatitis: A distinct form of chronic pancreatitis - An additional mimic of pancreatic neoplasms Academic Article uri icon

Overview

MeSH Major

  • Pancreatitis, Chronic

abstract

  • Follicular pancreatitis is a recently described variant of chronic pancreatitis characterized clinically by the formation of a discrete pancreatic mass and histologically by the presence of florid lymphoid aggregates with reactive germinal centers. Our aim was to study the clinical and histologic features of follicular pancreatitis, as well as to critically examine potential overlap with autoimmune pancreatitis. Immunohistochemistry for Bcl-2, CD21, κ and λ light chains as well as IgG4 and IgG were performed. We found a total of 6 patients (male-female ratio, 2:1; mean age, 57 years) who fulfilled the diagnosis of follicular pancreatitis in our institutions. Four had an incidental diagnosis, while two presented with abdominal pain, fatigue, and elevated liver enzymes. On imaging, 3 patients had a discrete solid mass, whereas 2 cases showed a dilated main pancreatic duct, mimicking an intraductal pancreatic mucinous neoplasm on imaging. One patient had a lesion in the intra-pancreatic portion of the common bile duct. On histopathology, all cases showed numerous lymphoid follicles with Bcl-2-negative germinal centers either in a periductal or in a more diffuse (periductal and intra-parenchymal) fashion, but without attendant storiform fibrosis, obliterative phlebitis, or granulocytic epithelial lesions. IgG4-to-IgG ratio was <40% in 5 cases. A comparison cohort revealed germinal centers in 25% of type 1 autoimmune pancreatitis and 2% of type 2 autoimmune pancreatitis cases, but none were periductal in location. In conclusion, follicular pancreatitis, an under-recognized mimic of pancreatic neoplasms is characterized by intrapancreatic lymphoid follicles with reactive germinal centers.

publication date

  • February 2016

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC5023064

Digital Object Identifier (DOI)

  • 10.1016/j.humpath.2015.09.017

PubMed ID

  • 26563969

Additional Document Info

start page

  • 154

end page

  • 62

volume

  • 48