Endoscopic ultrasound can differentiate high-grade pancreatic intraepithelial neoplasia, small pancreatic ductal adenocarcinoma, and benign stenosis

Objectives: High-grade pancreatic intraepithelial neoplasia (HG-PanIN) and invasive pancreatic ductal adenocarcinoma (PDAC)≤10mm are attractive targets. This study aimed to identify specific endoscopic ultrasound (EUS) findings for these detection.
Methods: Patients with surgically resected HG-PanIN (n=29) and PDAC≤10mm (n=11), or benign main pancreatic duct (MPD) stenosis (n=20) were retrospectively included. Six features differentiating between these lesions were examined by EUS video analysis, including MPD stenosis, MPD dilation, hypoechoic areas surrounding MPD irregularities (light gray mottled areas without demarcation or dark round areas with demarcation), branch duct dilation, prominent lobular segmentation, and atrophy.
Results: In logistic analyses, hypoechoic areas surrounding MPD irregularities were observed significantly more frequently in HG-PanIN (82.8%) and PDAC≤10mm (90.9%) than in benign stenosis (15.0%) (P<0.001 and P=0.002, respectively). HG-PanINs exhibited light gray mottled hypoechoic areas more frequently (79.3% vs. 18.9%) and dark round hypoechoic areas significantly less frequently than PDAC≤10mm (3.4% vs. 72.7%, P<0.016). The sensitivity and specificity of hypoechoic areas for differentiating HG-PanIN, PDAC≤10mm, and benign stenosis were 85.0% and 85.0%, respectively. The interobserver agreement by two blinded observers was moderate (kappa-value: 0.51).
Conclusions: Hypoechoic areas surrounding MPD irregularities on EUS may help differentiating between HG-PanIN, PDAC≤10mm, and benign stenosis.