Follicular pancreatitis: A rare pancreatic inflammatory pseudotumor

Authors：W James Tom; Xiangdong Xu; Noushin Vahdat; Fiona Cassidy; Lejla Aganovic

Source：CLINICAL IMAGING, 2020, 59(1): 39-44.

DOI：10.1016/j.clinimag.2019.08.006

• Follicular pancreatitis
• Chronic pancreatitis
• Mass-forming pancreatitis

Inflammatory pseudotumors imitate neoplasms on imaging but actually represent focal inflammation. We report a case of follicular pancreatitis, which is a recently recognized distinct form of mass-forming focal chronic pancreatitis pathologically characterized by lymphoid infiltration with abundant reactive germinal centers. In our patient, follicular pancreatitis manifested as a pancreatic tail mass that was resected due to imaging findings, which were suggestive of pancreatic malignancy. We performed a literature review of this rare condition and present a summary of reported imaging findings. The most distinguishing feature from pancreatic adenocarcinoma is the enhancement pattern, as follicular pancreatitis enhances more than the surrounding pancreatic parenchyma on delayed post-contrast images which is unusual for pancreatic adenocarcinoma. If this benign diagnosis is suggested on imaging, unnecessary surgery and its potential complications may be avoided.