Immune Checkpoint Inhibitor-Related Epidermal Necrosis: Terminology, Pathology, and Clinical Implications.

Area of Science:

• Immunology
• Dermatology
• Oncology

Background:

• Immune checkpoint inhibitors (ICIs) are vital cancer therapies but can cause severe cutaneous adverse events.
• ICI-related epidermal necrosis (ICIREN) presents a diagnostic challenge, mimicking Stevens-Johnson syndrome/toxic epidermal necrolysis.
• Growing evidence suggests ICIREN may be a distinct clinicopathologic entity.

Purpose of the Study:

• To review the literature on ICI-related epidermal necrosis (ICIREN).
• To examine ICIREN's terminology, histopathology, clinical course, pathophysiology, and diagnostic implications.
• To provide guidance for pathologists and clinicians in managing ICIREN.

Main Methods:

• Systematic literature search of PubMed and conference proceedings.
• Inclusion of case series, retrospective reviews, and mechanistic studies on ICIREN.
• Focus on clinicopathologic correlation for diagnosis and management.

Main Results:

• ICIREN can present with delayed onset, variable progression, and limited mucosal involvement.
• Distinct histopathologic features include lichenoid interface dermatitis and adnexal involvement.
• Early diagnosis and management may permit continued ICI therapy.

Conclusions:

• ICIREN represents a spectrum of reactions distinct from classic Stevens-Johnson syndrome/toxic epidermal necrolysis.
• Understanding ICIREN's unique features is crucial for accurate diagnosis and patient management.
• Multidisciplinary collaboration and clinicopathologic correlation are essential for optimizing outcomes in ICIREN.