A case of Ts1 cancer of the pancreatic tail discovered upon acute aggravation of chronic pancreatitis

A 65-year-old man was diagnosed with acute pancreatitis and admitted to our hospital. The disorder was improved by conservative therapy and the patient was discharged. However, acute pancreatitis recurred on the same day and the patient was re-admitted. Abdominal CT did not show any significant tumor in the pancreas. MRCP detected localized stenosis and dilatation of the pancreatic duct in the pancreatic tail, and acute aggravation of alcoholic chronic pancreatitis was suspected. ERCP detected obstruction of the main pancreatic duct in the pancreatic tail. EUS detected a hypoechoic tumor with a clear boundary and an irregular margin measuring 13.9×10.8mm in the pancreatic tail. A diagnosis of cancer of the pancreatic tail complicating alcoholic chronic pancreatitis was made, and pancreatectomy of the pancreatic tail was performed. A tumor measuring 1.3×1.0cm was observed in the pancreatic tail in the excised preparation. The histopathological findings showed the feature of usual invasive ductal carcinoma and papillary adenocarcinoma was partially observed. For early detection of small pancreatic cancer, thorough examination by EUS and ERCP is necessary, even if US or CT fails to reveal a tumor even for patients admitted for pancreatitis.