Diagnostic value of indirect imaging findings for high-grade pancreatic intraepithelial neoplasia: A multicenter study.
Abstract
Background
Pancreatic intraepithelial neoplasia (PanIN), a microscopic precursor of pancreatic ductal adenocarcinoma, cannot be directly visualized by conventional imaging. Secondary parenchymal and ductal changes-focal pancreatic parenchymal atrophy (FPPA), main pancreatic duct (MPD) abnormalities, and cystic lesions-have been proposed as indirect imaging findings (IIFs), but their diagnostic relevance remains uncertain. We investigated the association between specific IIFs and histopathologically confirmed malignant lesions in patients undergoing pancreatectomy without a detectable mass.
Methods
In this retrospective cohort study, 155 consecutive patients at two high-volume centers who underwent pancreatectomy for suspected high-grade PanIN between October 2018 and January 2026 were included. Preoperative imaging was reviewed to identify and map three IIF types (FPPA, MPD abnormalities, and cystic lesions) to surgical specimens, which were evaluated histopathologically.
Results
Of 155 patients, 94 (60.6%) had malignant lesions, including 77 (49.7%) high-grade PanIN, 14 (9.0%) invasive PDAC, and three (1.9%) non-invasive intraductal papillary mucinous carcinoma. Among 357 anatomical sites with IIFs, 125 (35.0%) contained malignancy. The positive predictive value increased with the number of overlapping IIF types: 20.7% for one, 38.5% for two, and 77.1% for three (p for trend < 0.001). Invasive PDAC occurred only at sites with multiple overlapping IIFs, in 5.2% and 14.6% of sites with two and three IIF types, respectively (p for trend < 0.001).
Conclusions
A combination of IIFs was associated with a high-risk pancreatic phenotype linked to high-grade PanIN and early pancreatic cancer. Multiple IIFs may help identify patients who warrant further diagnostic evaluation and facilitate risk stratification.