Xanthogranulomatous pancreatitis mimicking potentially malignant pancreatic neoplasm: report of a case.

Xanthogranulomatous pancreatitis (XGP) is a rare benign disease that may mimic or accompany other pancreatic diseases. Here we report a case of XGP initially suspected as malignant cystic neoplasm of the pancreas. A 64-year-old man had been incidentally found to have hypodense lesion at the body of pancreas during a lung cancer workup. All laboratory tests were within normal limits except that carcinoembryonic antigen was elevated to 31.3 ng/ml. Imaging study showed 1.8 cm sized, well demarcated, and low-attenuated mass on computed tomography (CT) with heterogeneously high intensity on T2-weighted images of magnetic resonance imaging (MRI). Under the impression of pancreas cystic neoplasm as a rare case of male solid-pseudopapillary tumor or pancreatic metastasis of lung cancer, laparoscopic distal pancreatectomy was performed. Microscopically, the mass had many foamy histiocytes with cholesterol clefts, consistent with xanthogranulomatous inflammation. Therefore, it is important to consider XGP in the differential diagnosis of pancreatic diseases.