A ganglion cyst is the most common soft tissue tumor in the hand and wrist. The most common of these benign tumors is a ganglion cyst appearing on the dorsum (or back) of the wrist, just past the skin crease where the wrist bends back and forth. This cyst comes from a specific joint between two bones in the wrist called the scaphoid and lunate bones.
These cysts almost always come from joints and may start in any joint in the hand or wrist. Another one of the most common places for a cyst is the dorsum of the finger between the skin creases of the end knuckle (DIP joint) and the start of the fingernail.
Most hand surgeons believe that the majority of cysts happen after some sort of trauma to the involved joint. A small hole develops in the joint lining and allows fluid to escape – the fluid forms a cyst.
What Is a ganglion cyst?
A ganglion cyst is a very common bump or mass that usually appears near joints or tendons in the hand or wrist. Common locations include the dorsal (back side) surface of the wrist, the palm side of the wrist, the base of the palm side of the finger, and the dorsal surface of the end joint of the finger.
You can envision what a ganglion cyst looks like by picturing a balloon filled with clear jelly, attached to a hollow stalk that comes from the joint or tendon lining. Fluid travels from the joint or tendon sheath into the stalk, and fills the balloon with fluid.
Constant motion of the hand or wrist keeps fluid pumped into the cyst and it can’t get back out. Ganglion cysts can be uncomfortable if they put pressure on nerves, tendons, or skin.
The good news is that they may go up and down in size or even go away completely on their own, without any needles or surgery. They may not be painful. Ganglion cysts are not malignant (they are not made up of cancer cells) and they don’t spread to other areas, though they may get larger or more lobulated (more lumpy).
How is the diagnosis made?
Diagnosis is based on the patient’s history (how he or she noticed the mass), where the lump is and what it feels like. Sometimes patients say they remember injuring the hand or wrist several weeks before noticing the cyst, but most patients can’t remember a specific event.
Cysts are usually round and firm. You can usually feel the smooth edges of a ganglion cyst, and you can often move the cyst around under the skin with your fingers. Cysts at the base of the finger are usually firm, pea-sized bumps that hurt when gripping narrow objects, like a steering wheel or suitcase handle.
Putting a flashlight on the skin around the mass will make it “light up” in a darkened room (transillumination), indicating that the mass has clear fluid inside.
Cysts at the end of the finger (DIP joint cysts) near the fingernail may push on the growing nail, causing a groove in the nail. Sometimes these may drain if the skin above them gets too thin.
I usually get x-rays to look at the bones and joints around the cyst. Sometimes I can see some nearby arthritis that explains the source of the cyst fluid, but in young people there is rarely an obvious source of the mass on x-rays. Rarely a cyst will be a sign of a serious ligament injury that hasn’t been diagnosed yet.
What is the best ganglion cyst treatment?
There are non-surgical treatment options for ganglion cysts; for cysts on the wrist and cysts on the finger. The first option is to do nothing – the mass may just go away on its own. If the cyst is not painful, not limiting activity, and not too big or uncomfortable, this is a good option.
Puncture or aspiration is the next thing to consider. Putting a needle in the mass may decompress it and allow the fluid inside to escape under or through the skin. Depending on where the cyst is, it may be near nerves or a major artery – make sure the doctor or nurse putting a needle in your cyst knows where these structures are.
I use the term puncture because it’s very difficult to draw out the thick clear jelly that’s often inside ganglion cysts. Usually, if the cyst is close to the skin, the jelly comes out through the hole made by the needle. I use a numbing shot first, then a larger needle to make a small hole in the wall of the cyst. I recommend a splint after this to allow the cyst wall to seal off. This is done in the office.
In my experience, cysts usually come back after puncture. The longer the cyst has been there, the less likely non-surgical treatment will work.
Finally, taking the cyst out in surgery is the most reliable way of getting rid of it. Ganglion cyst excision is not just a matter of opening up the skin and “lopping it off”; the joint or tendon sheath must be exposed to get out the stalk, or root of the cyst.
This can be done with a small incision over the cyst or through a wrist scope (camera inserted into the wrist joint). The exact method used depends on the size and location of the mass. Recurrence rates (chances of the cyst coming back) are very low – close to 3%.
Restrictions after ganglion excision surgery
For patients with wrist ganglion cysts, I recommend using a wrist splint after surgery for two weeks while the soreness from the surgery goes away. During that time, I advise patients to come out of the splint three times a day and do some stretching exercises. Patients can type and do light activities with their hands during this time.
Activity is rarely limited after finger or tendon cyst excision. Full use is usually allowed when the skin is healed after a few days.