Sometimes a small cyst or ganglion will form on the toes at the joint just behind the toe nail. If punctured a thick gelatinous fluid escapes. These are technically tiny toe ganglions but in this location they are more correctly knows as a mucked cyst. They are frequently treated by a "puncture" and the injection of a bit of cortisone. Unfortunately they often recur. A more permanent correction involves the removal of a little bone. This second picture is a copy of the x-ray of this patient's toe. In this patient there is an unusual proliferation of bone at this joint. This lady has a diagnosis of osteoarthritis (degenerative joint disease). The swelling in this part of the toe is called Heberden's Nodes.
In the picture the same 4th toe as pictured above has been raised so that you can see if from the side 
Solving this problem will require a "hammertoe" surgery that can be done in the office with local anesthesia or the surgery center under local anesthesia with a bit of sedation. A surgical shoe will need to be worn for a week or two followed by a tennis shoe for another week or so.
This is a photograph of another woman with a little ganglion on her the inside of her right 4th toe. It is that little swelling just below the center of the picture. I injected this lesion with a little cortisone twice and it has remained steadfast. She has elected to remove the lesion and I can do this under local anesthesia right in the office.
Mucoid cyst on the top of a toe in all its glory. This is a fluid filled cyst that balloons out from the underlying joint (much like the inner tube of a bicycle tire can squeeze out between the cracks of an old tire). Sometimes these pesky little things will go away by puncturing the cyst with a needle (of course, after anesthetizing the toe first!) and injecting a drop or tow of cortisone. Most of the time they come back after this kind of I&D (incision and drainage) and they need to be removed surgically. Even surgery will fail if you are not aggressive and take the entire cyst, down to the bone.
