Zosteriform Metastases from Malignant Melanoma
A 30-year-old man with a history of metastatic malignant melanoma presented with painful and itchy papulonodular lesions on the right side of his trunk (Panel A) that had developed over a period of 7 days. A computed tomographic scan showed extensive metastatic disease with necrosis throughout the right axilla and right lateral chest wall. The lesions were adjacent to the site of excision of the primary melanoma. The dermatomal distribution prompted a diagnosis of herpes zoster infection, and acyclovir was administered but with little response. A dermatologist made a diagnosis of zosteriform metastases caused by the metastatic malignant melanoma, although other considerations included postherpetic granulomatous dermatitis and cutaneous sarcoidosis. The patient was treated with vemurafenib, an oral selective BRAF inhibitor, and within 2 weeks after the start of treatment, the zosteriform lesions had dissipated (Panel B). After 140 days of treatment, meningeal metastasis developed, and treatment with vemurafenib was therefore stopped.
