POSITIVE PREDICTIVE VALUE OF MAIN PANCREATIC DUCT DILATION FOR MALIGNANCY PREDICTION IN SOLID PANCREATIC MASSES: A SINGLE-CENTER RETROSPECTIVE ANALYSIS

Aims To evaluate the association between main pancreatic duct (MPD) dilation and malignancy occurrence in pancreatic solid lesions during endoscopic ultrasound (EUS).

Methods Retrospective data from consecutive patients (Jan/2016 to Dec/2018) with solid hypoechoic pancreatic lesions on EUS was prospectively analyzed. The MPD diameter were measured in all patients. All solid lesions were punctured via fine-needle aspiration for histological analysis. Malignancy was defined in accordance with histological, surgical specimen and/or 6-months follow up. MPD diameter cut-off value for malignancy was estimated using Youden’s index. A sub-analysis with lesion localization, MPD diameter, EUS and EUS-guided fine-needle aspiration biopsy for determining sensitivity, specificity, positive and negative predictive values (PPV/NPV) for malignancy was calculated. Data was analyzed in Rv.3.6.0.

Results 119 patients with pancreatic hypoechoic lesions were included for analysis. The mean age was 64.7 ± 14.4 years, and 59/119 (49.6%) female. Most lesions were in the head of the pancreas (91/119; 76.5%) or uncinate process (10/119; 8.4%), with a median size lesions of 34 mm (range: 10–70). According to histology, 96/119 (80.7%) subjects had malignant lesions, follow up confirmed malignancy in 101/114 (88.5%), with 5 patients lost during follow-up. The median pancreatic duct diameter was 4.0 mm (range: 1.2–13.0) in the malignant group and 4.2 mm (range: 1.3–7.0) in the non-malingant lesions (p = 1.000). For both head and overall pancreatic lesions, an MPD diameter cut-off value > 5.2 mm as a marker of malignancy was estimated. According to our results, sensitivity, specificity, PPV and NPV for determining malignancy through MPD diameter > 5,2 mm was: 25%, 89%, 95%, and 12%, respectively; overall EUS: 93%, 77%, 97% and 59%, respectively; for EUS-guided fine-needle aspiration biopsy: 95%, 100%, 100% and 72%, respectively.

Conclusions A dilated MPD diameter > 5.2 mm in the context of solid pancreatic masses represents a useful indirect parameter for suspected malignancy.