# Two Ducts, One Drug—Pembrolizumab-Induced Pancreatic Injury Manifesting as Double-Duct Sign

## TL;DR

A rare case of pembrolizumab-induced pancreatic injury showed a double-duct sign, a radiological feature typically linked to cancer, and improved with endoscopic treatment.

## Contribution

First reported case of ICI-induced pancreatic injury presenting with a double-duct sign and responding to endotherapy.

## Key findings

- Pembrolizumab can cause pancreatic injury with a double-duct sign on imaging.
- Endoscopic retrograde cholangiopancreatography with stent placement improved the condition rapidly.
- The double-duct sign is a novel radiologic feature associated with ICI-induced pancreatic injury.

## Abstract

Immune checkpoint inhibitors (ICIs) can rarely result in ICI-induced pancreatic injury (ICI-PI). Its clinical and radiologic presentation is heterogenous, ranging from asymptomatic radiological signs to severe pancreatitis. Management is mainly with supportive measures and drug discontinuation. In this study, we present an unusual case of ICI-PI, secondary to pembrolizumab, resulting in dilation of both pancreatic and common bile ducts, displaying a “double-duct” sign on imaging. This radiologic sign, commonly associated with malignancy, has not been previously reported with ICI-PI. Endoscopic retrograde cholangiopancreatography with plastic stent placement resulted in quick improvement, highlighting the potential role of endotherapy in treatment of ICI-PI.