black spots on ears

Question
Hi,
Kenzie is a 21/2 old female boxer.  Over the last month she has developed small (the size of a pencil eraser) black spots on the inside flaps of her ears.  I had her to the vet who said she had never seen them before but didn't seem concerned about them.  Do you know what they could be?  I read Boxers are prone to cancer...could they be cancer.  They are not raised at all.  She has 2-3 on each ear.  
Thanks for your help

Answer
If your vet didn't bother to test her ears, taking a skin scraping, etc., then I highly recommend you change vets.

You need a vet that will test and diagnosis the problem then treat it.

This is inexcusable.

As far as what it is, I couldn't say, as all I could think of is ear mites or fleas.