Fig. 1

a-b Clinical manifestation of the patient: left-sided swelling and congenital melanocytic nevus on the left temporal area. The lesion was flat with irregular boundary and hypertrichosis. c T2-weighted post-contrast magnetic resonance imaging (MRI) axial view demonstrated heterogeneous enhancement of fossa cranii media, basis cranii, and temporal area on the right, as well as compression and displacement of left temporal lobe, consist with the diagnosis of vascular malformation. d The infiltrated melanocyte in the epidermis and dermis in the microscopic study (hematoxylin–eosin, original magnification × 100). e Sanger sequence of germline mutation of MAP2K1(15:66782840 G > A). f Sanger sequence of somatic mutation of BRAF (7:140453136 A > T)