Cutaneous sarcoid-like drug reaction caused by an anaplastic lymphoma kinase inhibitor.

Anaplastic lymphoma kinase (ALK) rearranged lung cancers represent 4% to 6% of all pulmonary adenocarcinomas, and echinoderm microtubule associated protein like 4 (EML4)-ALK fusions are the most common subgroup. Herein, we report a case of two successive drug reactions due to ALK inhibitors. A 69-year-old female with stage IVB EML4-ALK fused lung adenocarcinoma developed a generalized morbilliform eruption 10 days after starting alectinib. Skin biopsy findings were consistent with a drug reaction. Her findings resolved after alectinib was discontinued. Another ALK inhibitor, lorlatinib was started and she developed multiple asymptomatic cutaneous and oral nodules 4 months later. Biopsies from these nodules showed sarcoidal granulomas without evidence of metastases or infection. ALK inhibitors are associated with numerous adverse events, including various cutaneous eruptions. However, a sarcoidal drug reaction involving the skin has not been reported. Identification of drug reactions to targeted therapy can avoid long-term sequelae and misinterpretation of the clinical findings as disease progression or infection.