[Abdominal immune-related adverse events : Abdominal focus]

With the increasing use of immune checkpoint inhibitors (ICI) and chimeric antigen receptor (CAR)-T cell therapies in modern oncology, immune-related adverse events (irAEs) are being observed more frequently, often with abdominal manifestations. In addition to clinical symptoms and laboratory changes, radiologic imaging plays a key role in diagnosing these events and assessing their severity.

The aim of this review is to summarize the main abdominal irAEs following ICI and CAR‑T therapy, describe their imaging features, and outline important differential diagnoses.

A narrative literature review of clinical studies, meta-analyses, and guidelines on abdominal irAEs associated with immunotherapy was conducted.

ICI-induced irAEs include enteritis/colitis, hepatitis, cholangitis, cholecystitis, pancreatitis, interstitial nephritis, and adrenalitis. CAR-T cell therapies are primarily associated with cytokine release syndrome and neurotoxic events; abdominal manifestations typically show nonspecific inflammatory patterns. Although imaging findings are sometimes nonspecific, radiology contributes valuable information to personalized cancer therapy and complication management through interdisciplinary correlation with clinical and laboratory data as well as disease course.

Abdominal irAEs are not uncommon. Awareness of their characteristic imaging patterns and possible complications is essential for accurate differential diagnosis.