Gefitinib-associated lichen planus pigmentosus-like eruption

Area of Science:

• Oncology
• Dermatology
• Pharmacology

Background:

• The epidermal growth factor receptor (EGFR) pathway is crucial in non-small cell lung cancer (NSCLC).
• Gefitinib, a first-generation EGFR-tyrosine kinase inhibitor (TKI), targets this pathway.
• Cutaneous adverse effects are known complications of EGFR inhibitors (EGFRi).

Observation:

• A 62-year-old woman with NSCLC developed symmetrical, slate-gray-to-brownish-black macular pigmentation.
• The hyperpigmentation affected both sun-exposed and non-sun-exposed areas.
• These symptoms appeared after eight months of gefitinib treatment.

Findings:

• The patient's clinical presentation was consistent with lichen planus pigmentosus.
• Cutaneous hyperpigmentation is identified as a rare side effect of EGFR inhibitors.
• This case documents an unusual presentation of hyperpigmentation in a patient on EGFR-TKIs.

Implications:

• This case underscores the importance of recognizing rare dermatological side effects of EGFR inhibitors.
• Clinicians should be aware of potential hyperpigmentation syndromes associated with gefitinib therapy.
• Further investigation into the mechanisms of EGFRi-induced hyperpigmentation is warranted.