Sudden cafe-au-lait type spots w/ family history of Fanconi Anemia and Skin Cancer

I'm a 19 year old female. Within the past month or month and a half i've been noticing the skin on my arms darkening and getting splotchy. (To me, it looks alot like cafe-au-lait spots, but they have never been there before). They go from my shoulder all the way down to just below my elbow on both arms.
My nephew has Fanconi Anemia. I don't have any other symptoms of FA, and i know it would be really rare for it to go unnoticed this long, but the sudden apperance the cafe-au-lait spots on my arms has me a little concerend/confused.
I have a family history of Skin Cancer as well, from multiple family members.
Should this sudden change in my arms be cause for concern??