I m a 25 years old, 6ft tall male weighing 160lbs. Within the last 5 days, I ve noticed about 15 brown spots on my skin. 2 of them are birthmarks which used to be very small but they have grown in size along with the new brown spots. They are on my face and arms, although the 2 birthmarks are on my torso and shoulder which usually get no sun exposure. Are these sun spots and are there any malignant potential? Thanks.