13 Year Old Has Spider-like Vein Bruising In Both Upper

13 year old has spider-like vein bruising in both upper arms- no injuries to account for these small dime sized bruises. No loss of appetite, changes in sleep, itchiness, or fever. She has a lump in her neck that was checked about a month ago and they said it should go down, however lump has gotten slightly larger. Lump is not painful and moves a bit with the same area.