Evaluation of efficacy of pancreatic juice cytology for risk classification according to international consensus guidelines in patients with intraductal papillary mucinous neoplasm; a retrospective study.

OBJECTIVES

Pancreatic juice cytology (PJC) for intraductal papillary mucinous neoplasm (IPMN) is a possible tool to enhance preoperative diagnostic ability by improving risk classification for malignant IPMN, but its efficacy is controversial. This study evaluated the efficacy of PJC for risk classification according to international guidelines.

METHODS

We retrospectively analyzed 127 IPMN patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) preoperatively. PJC was performed in 125 of the 127 cases. High-risk stigmata (HRS, n = 57), worrisome features (WF, n = 64), and other characteristics (n = 6) were classified according to the 2017 international guidelines.

RESULTS

Among the 127 IPMN patients, 71 (55.9%) had malignant IPMN (invasive and non-invasive intraductal papillary mucinous carcinoma). The accuracy of WF for classifying malignant IPMN was increased by the addition of PJC, but the accuracy of HRS was not (WF to WF + PJC: 33.1% [42/127] to 48.8% [61/125], HRS to HRS + PJC: 65.4% [83/127] to 52.8% [66/125]). Post-ERCP pancreatitis (PEP) occurred in 32 (25.2%) of 127 IPMN patients. Severe PEP was not detected. Significant risk factors for PEP were female sex, obesity, and endoscopic naso-pancreatic drainage (ENPD) (P = .03, P = .0006, and P = .02, respectively). In patients with ENPD tube placement, a main pancreatic duct size of <5 mm was a significant risk factor for PEP (P = .02).

CONCLUSION

PJC could increase the accuracy of WF for classifying malignant IPMN. The additive effect of PJC for risk classification may be limited, however, and it is not recommended for all IPMN cases due to the high frequency of PEP.