Papular nevus spilus syndrome: old and new aspects of a mosaic RASopathy

The co-existence of papular nevus spilus (PNS) and ipsilateral extracutaneous abnormalities involving peripheral nerves of the skin or muscles was originally described as "speckled lentiginous nevus syndrome". To avoid confusion with macular nevus spilus, the condition was recently re-named "papular nevus spilus syndrome". In addition to 14 published cases, we identified six new cases via a search of the worldwide literature. New diagnostic...