Angiokeratoma circumscriptum arranged in a systematized band-like pattern suggesting mosaicism.

A 10-year-old girl with vascular lesions that had been present since birth is reported. Initially, small red macules were limited to the legs, but later the lesions became more extensive. A hyperkeratotic aspect of the lesional skin surface had developed at the age of 2 years. On clinical examination, hyperkeratotic vascular lesions in a band-like distribution on the trunk, legs and face were observed. The type of lesion varied from discrete macules with no or slight hyperkeratosis to confluent, protruding verrucous plaques. The clinical and histopathological findings were consistent with a diagnosis of angiokeratoma circumscriptum. The systematized band-like arrangement observed in the present case strongly supports the concept that angiokeratoma circumscriptum reflects a mosaic state of a mutation that is so far unknown.