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Published on: September 8, 2021
BRAF Inhibitor-Induced Antitumoral Granulomatous Dermatitis Eruption in Advanced Melanoma
Maria C Garrido1, Carlota Gutierrez, Erica Riveiro-Falkenbach
1Departments of *Pathology, and †Dermatology, Hospital Universitario 12 de Octubre, Universidad Complutense, Instituto de Investigación I+12, Madrid, Spain.
Abstract:
Recent advances in targeting BRAF mutations, which occur in roughly 50% of the melanomas, have improved response rates and overall survival in patients with advanced disease. With the increasingly extensive use of the drug, new, nonpreventable, cutaneous and noncutaneous toxicities keep arising as infrequent adverse effects. We report a 55-year-old man with a history of metastatic melanoma treated with the dabrafenib who presented, 10 months after the initiation of the treatment, with erythematous, slightly squamous, round plaques on his upper trunk and on his left upper arm. Two skin biopsies from the lesions revealed a granulomatous dermatitis in the superficial reticular dermis. One of them showed admixed abundant melanophages from tumoral melanosis. No melanoma cells were seen in any of the specimens. No interruption of the treatment was necessary. Our observation indicates that such a response may represent a positive immune activation triggered by BRAF inhibitors. The erythematous rash was initially concerning for progression of metastatic disease, which suggests that a close monitoring of the patients with advanced melanomas treated with vemurafenib is advisable to prevent unnecessary discontinuation of the therapy.
Insights
BRAF inhibitors like dabrafenib can cause granulomatous dermatitis in melanoma patients. This rash may indicate positive immune activation, not disease progression, warranting careful monitoring.
Area of Science:
- Oncology
- Dermatology
- Immunology
Background:
- BRAF mutations are common in melanoma, and targeted therapies have improved patient outcomes.
- BRAF inhibitors, such as dabrafenib, are increasingly used for advanced melanoma.
- Adverse effects, including cutaneous toxicities, can arise with BRAF inhibitor therapy.
Observation:
- A 55-year-old man with metastatic melanoma developed erythematous, squamous plaques after 10 months of dabrafenib treatment.
- Skin biopsies revealed granulomatous dermatitis with melanophages, but no melanoma cells.
- The patient's condition did not necessitate treatment interruption.
Findings:
- The observed granulomatous dermatitis is a potential indicator of immune activation induced by BRAF inhibitors.
- This reaction can mimic melanoma progression, highlighting the need for accurate diagnosis.
- The findings suggest that BRAF inhibitors may stimulate an anti-tumor immune response.
Implications:
- Close monitoring of patients with advanced melanoma receiving BRAF inhibitors is crucial.
- Distinguishing drug-induced rash from disease progression prevents unnecessary treatment discontinuation.
- Understanding these immune-related adverse events can optimize melanoma treatment strategies.
