Challenging diagnosis of a resected pancreatic pseudocyst accompanied by cholesterol granuloma

Abstract

A 52-year-old man, who had been monitored for the last two years due to a pancreatic cystic lesion in the tail of his pancreas, was referred to our hospital after a recent MRI revealed a new cystic lesion measuring 45 mm in the same location. A contrast-enhanced CT scan showed low density inside the cystic lesion. Endoscopic ultrasound identified a papillary mass inside the cyst at the tail of the pancreas and an irregular hypoechoic mass lesion on the pancreatic head side. Furthermore, endoscopic retrograde pancreatography showed disruption of the main pancreatic duct in the tail of the pancreas. As the possibility of pancreatic cancer could not be ruled out, a laparoscopic distal pancreatectomy was performed. The tumor lesion was brownish-yellow in color, with clear margins and contained muddy deposits. Histopathological analysis identified cholesterol crystals surrounded by foreign body giant cells, and the tumor was ultimately diagnosed as a pseudocyst accompanied by cholesterol granuloma.