Pyogenic granuloma (PG) is a common benign vascular skin lesion presenting as a rapidly growing angiomatous papule. The pathogenesis of most sporadic PGs and PGs associated with port wine stains (PWSs) remains elusive. We report that of 10 PGs secondarily arisen on a PWS, 8 showed a BRAF c.1799T>A (p.(Val600Glu)) and 1 a NRAS c.182A>G (p.(Gln61Arg)) mutation. The GNAQ c.548G>A mutation was identified in the PG and in the respective underlying PWS, indicating that PGs originate from cells of the PWS.
