<s>[INST] I have a bump under the surface of the skin located on the left side of the left foot half way up the shoe lace area between the sole and the shoe lace.  It is not noticeable to the eye but if you lightly run your finger over the surface it is easy to feel.  if you press on its forward or aft side it is very painful.  As of now it has little effect while walking but is very painful while sleeping. [/INST] Hello,As per my surgical experience, the lump between the foot and shoelace area, not prominent on skin indicates possible developing bursa cyst or ganglion.An ultrasound examination will be confirmatory for the diagnosis.Hope I have answered your query. Let me know if I can assist you further.Regards, Dr. Bhagyesh V. Patel </s>