Images of EUS and pathological features in cases with carcinoma in situ of the pancreas

Backgrounds: Pancreatic carcinoma is hard to diagnose in the early stage. In our doctor communities around Onomichi City, the screening consensus including EUS between high volume centers and regional doctors has been established in the early diagnosis of small pancreatic carcinoma. In this study, we report the images of EUS and pathological features in cases with carcinoma in situ of the pancreas.

Materials and Methods: From 2007 to 2010, we could diagnose 8 cases with carcinoma in situ of the pancreas with repeated cytology using pancreatic fluid collected by endoscopic nasopancreatic drainage (ENPD) preoperatively. EUS images of these cases were compared with their pathological features.

Results: EUS could not find out the direct tumor image, it could find out the indirect abnormal findings (dilatation or stenosis of pancreatic duct) in all cases. The irregular stenosis in main pancreatic duct was detected in all cases. The dilatation of the main pancreatic duct from the stenosis to the end of tail was detected in 6 out of 8 (75%). The low echoic zone around the irregular stenosis was detected in 3 out of 8 (38%). As for pathological features, the contents of carcinoma in situ located in the branch duct of the pancreatic duct in all cases. Additionally, in 4 out of 8 (50%), the cancer lesion also extended to the mucosal epithelium of the main pancreatic duct. Interestingly, the local pancreatitis around the main pancreatic duct beside the carcinoma in situ was frequently detected. The low echoic zone around the irregular stenosis detected by EUS identified to the local pancreatitis beside the cancer lesions.

Conclusions: The irregular stenosis, dilatation of the main pancreatic duct, and the low echoic zone around the irregular stenosis detected by EUS may be important for the initial screening of the carcinoma in situ of the pancreas.