Dermatology Online Journal

Agminated melanocytic nevus is an uncommon type of mole, characterized by a local group of macular or papular pigmented lesions, well demarcated, without a common pigmented background. This pattern has also been associated with Spitz nevi, dysplastic melanocytic nevi, and non-melanocytic lesions.We describe the onset of an acquired agminated melanocytic nevus after dabrafenib treatment. Our case highlights paradoxical MAPK activation in the setting of single-agent BRAF blockade and underscores the importance of characterizing the diverse side effects of selective BRAF inhibitors. This is the first case, to our knowledge, of agminated melanocytic nevus in association with dabrafenib.