Mast cell tumor on the inner thigh of a 10 year old <a href="//commons.wikimedia.org/wiki/English_springer_spaniel" title="English springer spaniel">Springer Spaniel</a>.
<a href="//commons.wikimedia.org/wiki/User:Joelmills" title="User:Joelmills">Joel Mills</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>