Type 2 segmental manifestation of multiple glomus tumors: A review and reclassification of 5 case reports

In various autosomal dominant skin disorders, segmental forms reflecting mosaicism have been reported. Recently, two different types of mosaic manifestation have been delineated. Type 1 reflects heterozygosity for the underlying mutation and shows a degree of severity as observed in the corresponding nonmosaic phenotype. Type 2 originates from loss of heterozygosity, shows an excessively severe involvement and is usually superimposed on the disseminated lesions of the ordinary trait.

We wanted to exemplify further the proposed rule of dichotomy.

We have screened the literature on multiple glomus tumors, a trait that follows an autosomal dominant mode of transmission.

We found 5 cases of multiple glomus tumors suggesting a type 2 segmental involvement. In all of these cases, a unilateral band-like or patchy arrangement of excessively pronounced glomus tumors was associated with disseminated lesions corresponding to the ordinary phenotype, and in 3 cases other family members were affected with disseminated glomus tumors. The unilateral agminated lesions were reported to be present in early childhood, whereas the disseminated lesions appeared later.

Multiple glomus tumors can be added to the list of autosomal dominant skin disorders that may show a type 2 segmental involvement.