Cutis verticis gyrata-like skin toxicity during treatment of melanoma patients with the BRAF inhibitor vemurafenib after whole-brain radiotherapy is a consequence of the development of multiple follicular cysts and milia

Excerpt

We read with much interest the report about patients with cutis verticis gyrata-like skin lesions that appeared during therapy with vemurafenib after whole-brain radiotherapy (WBRT;Harding et al. [1]). We also have observed a similar severe skin side effect after treatment of a patient with vemurafenib. The 58-year-old patient with metastases in the axillary lymph nodes and multiple symptomatic brain metastases received WBRT over 2 weeks in July 2013, with a total dose of 30 Gy (10 × 3 Gy; ◉ Fig. 1). Because the V600E mutation was identified, we started the BRAF inhibitor vemurafenib, at a dose of 960 mg b.i.d., 1 week after completion of WBRT. One week later the patient suffered a strong phototoxic reaction with blisters on the dorsi of both feet. We continued vemurafenib therapy with local steroid treatment and consequent sun protection. Four weeks after initiation of vemurafenib treatment, the patient developed erythema and severe thickening of the skin on the scalp and face (◉ Fig. 2). Hearing was impaired because of swelling of the ears, including the ear canal. We stopped vemurafenib and admitted the patient to hospital. Because, clinically, we expected a dense inflammatory infiltrate similar to that seen in actinic reticuloid, we took a biopsy and started the patient on intravenous steroid therapy with methylprednisolone 2 mg/kg/b.i.d. As a result of this treatment the mild erythema disappeared but the cutis verticis gyrata-like skin thickening remained. Unexpectedly, histologically the amount of inflammatory infiltrate was small, but multiple follicular retention cysts and milia were present (◉ Fig. 3). Hence, we stopped the steroid therapy and followed up the patient clinically. …