術前診断困難だったfollicular pancreatitisの1例

A case of follicular pancreatitis with difficulty in preoperative diagnosis

follicular pancreatitis（濾胞性膵炎）は，多数の反応性リンパ濾胞が膵実質において増殖する像を特徴とする膵炎の亜型として，Zenら^1）により2012年に世界で初めて報告された。その後も報告は少なく，その臨床的および画像的特徴や病因はいまだ明らかではない。今回，術前画像で膵腫瘍との鑑別が困難だったfollicular pancreatitisの1例を経験したので，若干の文献的考察を含め報告する。

We report a case of a follicular pancreatitis, which is a rare disease. A 80’s-year-old woman was introduced to our hospital for a detailed examination of a pancreatic body mass. On MR imaging, the lesion showed ill-defined margin, slight hyperintensity on T2- and diffusion-weighted images, and hypointensity on T1 weighted images. On dynamic contrast-enhanced CT, the lesion show gradual and persistent contrast enhancement. Neither irregularity nor narrowing of main pancreatic duct was identified on magnetic resonance and endoscopic retrograde cholangiopancreatography. Pancreatosplenectomy was performed, and the lesion was pathologically confirmed to be a follicular pancreatitis.