We sought to identify clinicopathological characteristics of high-grade pancreatic intraepithelial neoplasia (PanIN
)/carcinoma in situ
to facilitate screening for pancreatic ductal adenocarcinoma.
We evaluated PanIN
lesions in 173 consecutive autopsy cases with no evidence of pancreatic ductal adenocarcinoma and/or intraductal papillary mucinous neoplasm (mean age, 80.5 years) by submitting the entire pancreas
for microscopic examination.
-3 was found in 4% of examined cases, whereas PanIN
-1 and PanIN
-2 were present in 77% and 28%, respectively. PanIN
-3 was more frequently identified in patients with diabetes mellitus and/or older age. PanIN
-3 lesions were always multifocal, and the number of PanIN
-3 foci was positively associated with those of PanIN
-1 or PanIN
-3 was located more frequently in the pancreatic body and tail than in the head and predominantly involved small interlobular/intralobular ducts rather than the main duct. Notably, 71% of pancreata with PanIN
-3 showed cystic changes in PanIN
-3 and lower grade PanIN
-3 was also accompanied by higher grade extralobular fibrosis
We found that 4% of the examined pancreata harbored PanIN
-3 lesions that were associated with several unique clinicopathological features. The cystic change along with fibrotic pancreatic parenchyma may be detected by imaging studies such as endoscopic ultrasound.