a lump on the side of the foot - HELP!

hi! my name is Andrew, i live in Ukraine.

about 6 months ago (Feb 2011 or so) i first felt a lump under the skin of my foot, on the edge where the sole starts.

It is exactly where "inflammation" is shown in this picture, on inner side of the foot:

back then (in Feb) it just felt like a lump under the skin.

approx in June it became visibly protruding, and white if compressed (in contrast to surrounding tissue).

now (Aug) it is more protruding, if compressed it looks bluish in color and it started to HURT!

also, it itches inside, under the skin.

the skin surface in this spot is unaffected, and it is a thick, "fat" skin on the edge of the sole.

Please, help to determine what it might be??!