Photodynamic therapy for multiple eruptive keratoacanthomas associated with vemurafenib treatment for metastatic melanoma.

BACKGROUND: The development of keratoacanthomas (KAs) and well-differentiated squamous cell carcinomas (SCCs) is a known adverse effect of novel BRAF inhibitors such as vemurafenib. With multiple such neoplasms often arising after BRAF inhibitor therapy, surgical excision is often impractical.

OBSERVATIONS: We describe a patient with stage IV melanoma who received the BRAF inhibitor vemurafenib (recently approved by the US Food and Drug Administration) as part of a clinical trial and developed numerous diffuse, pathology-proven KAs and SCCs. The high number of lesions across a broad area precluded surgical treatment; instead, a noninvasive field approach using photodynamic therapy (PDT) was initiated. Compared with untreated tumors, most lesions demonstrated significant clinical regression following successive cycles of PDT.

CONCLUSIONS: Given vemurafenib's recent approval by the US Food and Drug Administration, we provide a timely case report on the effective use of PDT in the treatment of BRAF inhibitor-associated KAs and SCCs. Although further studies are needed to better understand the biological processes of these secondary neoplasms, our observation provides an alternative noninvasive solution for improving the quality of life for patients receiving BRAF inhibitor therapy.