Question
I have a skin colored bump on the back of my foot above my heel. I noticed it a few years ago. It's not painful but I think it is getting a little bigger and it has started to tingle on occasion. When I rub it, I think I can feel a solid something move back and forth under the skin. It grosses me out. Any ideas what it may be? It is starting to make me uncomfortable especially since there isn't one my right foot.

Answer
This could be a retrocalcaneal bursa which is a protective sack on the back of the heel.  this is more common in women because of the types of shoes you wear.  It could also be a ganglionic cyst which is a fluid filled mass.  both of these are benign. to be sure exactly what you have you should have an mri done.
good luck
Isaac Tabari DPM
www.footdocnyc.com

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