Optimal indication of adding pancreatic juice cytology in the diagnosis of malignant intraductal papillary mucinous neoplasm of the pancreas.

BACKGROUND/OBJECTIVES: Positive pancreatic juice cytology (PJC) is an important finding when considering surgical resection in patients with intraductal papillary mucinous neoplasm (IPMN); however, guidelines do not recommend endoscopic retrograde cholangiopancreatography (ERCP) for PJC. This study aimed to clarify the findings worthy of adding PJC for diagnosing high-grade dysplasia (HGD) and invasive carcinoma (IC) in patients with IPMN.

METHODS

Patients with IPMN who underwent preoperative PJC and surgical resection at Hiroshima University Hospital were enrolled, and the diagnostic yield of malignant IPMN based on PJC and clinical and imaging findings and the incidence of post-ERCP pancreatitis (PEP) were retrospectively analyzed.

RESULTS

Of the 129 eligible patients, 61 (47%) had malignant tumors (29 HGD and 32 IC). The diagnostic yields of PJC were as follows: 33%, 97%, 91%, 62%, and 67% for sensitivity, specificity, and positive predictive value, and negative predictive value, respectively. Multivariate analysis revealed that an abrupt change in the pancreatic duct caliber was an independent predictive factor of true-positive PJC (hazard ratio: 15.81, P = 0.001), with a diagnostic sensitivity of 86% for PJC in these patients. The incidence rate of PEP was 19%, and the pancreatic body and tail lesions, main pancreatic duct diameter <10 mm, and placement of a nasopancreatic drainage catheter were significant risk factors for PEP.

CONCLUSIONS

Although PJC is generally not recommended for patients with IPMN, it is worth considering for the determination of treatment strategies in patients with abrupt changes in the caliber of the pancreatic duct with distal pancreatic atrophy.