A case of stage IA pancreatic ductal adenocarcinoma accompanied with focal pancreatitis demonstrated by contrast-enhanced ultrasonography.

A patient with slight dilatation of the main pancreatic duct was followed-up with ultrasonography every 6 months as a high-risk case of pancreatic cancer. Twelve years later, a faint hypoechoic area 13 mm in diameter was first detected on the body of the pancreas. Contrast-enhanced ultrasonography revealed a well-demarcated hypoenhanced area 8 mm in diameter and a hyperenhanced area with an unclear margin. The former was suspected to be a small pancreatic cancer lesion, and the latter to be focal pancreatitis accompanying cancer. However, contrast-enhanced dynamic CT did not suggest any tumor, diagnosis of adenocarcinoma was confirmed with pancreatic juice cytology through endoscopic retrograde pancreatography. Surgical resection was performed, and the lesion was pathologically diagnosed as invasive ductal carcinoma as follows: pTS1 (1.0 cm), infiltrative type (pT1), stage IA. When comparing the images from contrast-enhanced ultrasonography with the pathological findings, the hypoenhanced area corresponded to ductal adenocarcinoma, and the hyperenhanced area to focal pancreatitis. Contrast-enhanced ultrasonography was able to reveal detailed information on the focal lesion in the pancreas, and it was effective for the early diagnosis of pancreatic cancer.