Pathology for early diagnosis of pancreatic cancer

Abstract

With the active imaging screening in Japan, previously difficult-to-diagnose intraepithelial carcinoma/high-grade PanIN and small pancreatic cancers are now being detected. Pathologically, high-grade PanIN is characterized by cylindrical dysplastic epithelium with enlarged nuclei, accompanied by polarity disturbance of the nuclei and pseudostratification, proliferating with low papillary structures within the pancreatic duct. There are morphological variations in high-grade PanIN. Understanding these pathological features directly contributes to improving the accuracy of cytological diagnosis. Furthermore, these pathological images may also be involved in the molecular abnormality patterns underlying carcinogenesis and their distribution within the pancreatic ducts. By classifying high-grade PanIN into "main pancreatic duct extended type," which proliferates mainly in the main pancreatic duct, and "parenchymal type," which is limited to the peripheral branch ducts, a deeper understanding of early-stage pancreatic cancer may be achieved. This paper provides an overview of the pathology of HG PanIN and its surrounding stroma.