Dermatologic toxicity from immune checkpoint blockade therapy with an interstitial granulomatous pattern

Area of Science:

• Oncology
• Dermatology
• Immunology

Background:

• Immune checkpoint inhibitors targeting CTLA-4 and PD-1/PD-L1 pathways offer significant benefits for advanced solid malignancies, including melanoma.
• However, immune-related adverse events (irAEs) are frequent, with emerging dermatologic toxicities requiring careful management.

Observation:

• A patient receiving combination immunotherapy (ipilimumab and pembrolizumab) for advanced melanoma developed asymptomatic erythematous patches on the legs.
• Histopathologic analysis confirmed a diagnosis of cutaneous interstitial granulomatous dermatitis.

Findings:

• The patient's granulomatous dermatitis did not necessitate interruption of immunotherapy.
• Dermatologic lesions remained stable, correlating with effective control of the patient's melanoma.

Implications:

• This case expands the known spectrum of dermatologic toxicities associated with immune checkpoint blockade.
• Recognizing and managing novel irAEs is crucial for optimizing patient care and maintaining therapeutic efficacy in cancer immunotherapy.