Type 2 segmental manifestation of "blue rubber bleb nevus syndrome": a reappraisal of 5 case reports.

"Blue rubber bleb nevus syndrome" is an autosomal dominant trait characterized by multiple cutaneous and extracutaneous angiomas of dark blue color and rubbery consistency. The lesions do not represent nevi, which is why a more appropriate term would be "blue rubber bleb angiomatosis". Here, 5 unusual case reports collected from the literature are revisited and re-classified as examples of a type 2 segmental manifestation of the disorder. According to this theory, an early postzygotic event of loss of heterozygosity gave rise to a pronounced mosaic involvement being superimposed on the ordinary, non-segmental phenotype. Hence, "blue rubber bleb nevus syndrome" can be added to the list of autosomal dominant skin disorders that may sometimes be complicated by a type 2 segmental involvement.