Subcutaneous non-capsulated hamartoma formed of intercommunicating microcystic vascular channels separated by incomplete and thick fibrous septa. Spaces are empty and lined by mature endothelium. No evidence of atypia or malignancy.
Small scalp mass.
Two fragments of collective size 1.7x1.3x0.7 cm partially covered by skin.
Scalp mass, excision biopsy: