I have iodine looking spots on the heal of my palm in 2 places and on the bottom of my thumb. also, on my pinky finger of the other hand.

Could be anything : It is very difficult to comment without seeing an image of these skin lesions. Please upload a picture or see a doctor for a proper exam and diagnosis

Depends: Whether or not to be concerned depends on how long they have been there and whether they are changing. Most long-standing stable ones are benign and just the way your body's pigment is distributed