Obstructive jaundice induced by a true cyst in the head of the pancreas

Abstract

A 63-year-old woman was found to have a 20 mm cystic lesion at the pancreatic head, 22 years previously. The lesion gradually increased from 30 mm two years previously to 37 mm in one year, with no evidence of malignancy, including an internal nodule, and we followed it up as a benign lesion. She had no past history of pancreatic injury or alcohol intake. She was admitted due to darkening of urine and an itching sensation. Blood analysis showed a slightly elevated total bilirubin level and liver function abnormality. Abdominal CT scan and MRI showed a 50-mm cystic lesion at the pancreatic head and dilatation of the intrahepatic bile duct, but no mass lesion was recognized in the cyst. ERCP showed compressive stenosis of the middle and lower bile duct and main pancreatic duct with dilatation of the intrahepatic bile duct and distal pancreatic duct. The cyst had no connection to the main pancreatic duct. We diagnosed obstructive jaundice induced by the cyst and performed subtotal stomach preserving pancreatoduodenectomy. Serous fluid was seen in the cyst. Histologically, the cyst was lined by a cuboidal epithelium and was finally diagnosed as a true cyst of the pancreas.