A ganglion cyst is a benign (non-cancerous), fluid-filled sac that develops next to a joint or tendon, most often on the wrist or hand. It forms when thick, jelly-like fluid collects in a small pocket that balloons out from the lining of a joint or tendon sheath. Ganglion cysts are the most common soft-tissue lump found in the hand and wrist.

These cysts can appear suddenly or develop slowly over time, and they often change in size - growing, shrinking, or sometimes disappearing on their own. Cysts on the back of the wrist tend to be the most noticeable, while smaller ganglions can stay hidden beneath the skin, where they may be felt more than seen.

Ganglion cysts most commonly appear on the back of the wrist, but they can also form on the palm side of the wrist, at the base of a finger, or at the end joint of a finger near the fingernail. Although a visible lump can be alarming, a ganglion cyst is not cancer and is usually harmless, though it can sometimes cause discomfort or limit movement depending on its size and location.

Many ganglion cysts cause no symptoms beyond a visible or palpable lump. When discomfort does occur, it often takes the form of aching, tenderness, or pressure - typically when the cyst presses on a nearby nerve or with certain wrist and hand movements. Pain is not a constant feature of a ganglion cyst, and many people have one without any discomfort at all.

How a ganglion cyst feels can vary widely from person to person. When a cyst does cause discomfort, it is often because it is pressing on a nearby nerve or interfering with movement, and symptoms may come and go as the cyst changes in size with activity.

Size does not always predict discomfort. In fact, it is frequently the small, hidden ganglions that cause the most discomfort, while larger cysts may be painless and primarily a cosmetic concern. Depending on the cyst’s location, some people also notice tingling, numbness, or weakness if it presses on a nerve, or reduced grip strength when it limits motion.

A ganglion cyst is usually diagnosed through a physical examination and a review of your symptoms. Because the cyst is fluid-filled, shining a light through it (a technique called transillumination) can help confirm the diagnosis. Imaging such as ultrasound or MRI is occasionally used to identify smaller, hidden cysts or to rule out other causes of a lump.

Care of the hand requires specialized attention because of its complexity. Dr. Cohen favors a conservative, non-surgical approach whenever possible. Many ganglion cysts respond well to non-surgical treatment, which may include observation, immobilization with a splint, medication to ease discomfort, and aspiration - drawing the fluid out of the cyst with a needle. Dr. Cohen will recommend the best course of care after a thorough examination.

When a ganglion cyst is painful, limits hand function, or returns after non-surgical treatment, surgery to remove it may be recommended. The procedure removes the cyst along with the small stalk that connects it to the joint or tendon sheath, which helps reduce the chance of it coming back. If you have a lump on your wrist or hand, Dr. Cohen can evaluate it and discuss the options best suited to your situation.