What Causes Bump Appearing In Site Of Previous Pilonidal Cyst?

I had a pilonidal cyst removed over a year ago. A month ago I had another procedure but the dr was not sure if it was the cyst returning or just infected scar tissue. I have been applying heat to alleviate discomfort from scar tissue and now I have another bump. Is the cyst coming back or can this bubble have appeared because of all he heat.