Diagnosis of pancreatic malignancies using an overnight-stored pancreatic juice cell block specimen

Background and aims

Pancreatic juice cytology is useful for diagnosing pancreatic duct strictures and cystic lesions. However, some cases cannot be diagnosed using cytology. This study aimed to evaluate the utility of the overnight-stored pancreatic juice cell block (CB) method for diagnosing pancreatic disease.

Methods

This retrospective study included 32 patients who presented with pancreatic duct strictures or cystic lesions between 2018 and 2024. The sensitivity, specificity, and accuracy of the CB method and single/multiple pancreatic juice cytology were compared to evaluate the utility of the CB.

Result

An endoscopic nasopancreatic drainage tube was placed in the main pancreatic duct, and pancreatic juice was collected to create a CB specimen. The median amount of pancreatic juice collected was 180(30–200) mL, and the median number of cytological examinations was three(2–8). Of the 32 cases, 13 were malignant, and 19 were benign (non-malignant). The sensitivity was significantly higher for the CB method (62 %) than for single cytology(15 %, P = 0.0414), and there was no significant difference between CB and multiple cytology(54 %, P = 1.0). The specificity and accuracy were not significantly different between the CB method and single or multiple cytology. When multiple cytology and CB were combined, sensitivity improved to 77 %. The pathological findings of the CB specimens were similar to the surgical specimens, including immunohistochemistry.

Conclusion

The overnight-stored pancreatic juice CB method was more effective than single cytology, with similar sensitivities to multiple cytology and can also be used for immunohistochemistry. The pancreatic juice CB method is useful for pancreatic juice assessment.