Unfortunately, since I can't see the area in question, it is difficult for me to guess. Possibly there is an accessory bone at the base of the 5th metatarsal which may still be cartilaginous. This is called an os vesalianum. I would recommend a MRI if there is pain involved.
Sorry I can't give you more help.
Posted By Vivian Abrams DPM on January 06, 2005 at 11:24:10: