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.