Phacomatosis pigmento-pigmentaria: the state of art

The term phacomatosis is used to indicate two or more different types of genetically determined cutaneous lesions are contemporarily present, such as phacomatosis pigmentovascularis or phacomatosis pigmentokeratotica. The first observation of a newborn presenting with segmental cafe au lait macules combined with an aberrant Mongolian spot, led some authors to hypothesize that this singular association was not a coincidence, but the result of twin-spotting phenomenon. In the analogy to other similarly named entities, they coined the term ‘phacomatosis pigmento-pigmentalis’.