Diagnosing Ganglion Cysts

Ganglion cysts are noncancerous lumps that develop along the tendons or joints of the wrists or hands and sometimes on the ankles or feet. They can range in size, from as small as a pencil eraser to as large as a golf ball. These cysts fill with fluid from a nearby joint and can quickly appear, disappear, or change in size.

Most ganglion cysts form a visible lump on the surface of the skin, but sometimes they remain “occult”—hidden under the skin. Ganglion cysts do not typically cause discomfort, but if a cyst puts pressure on the nerves that pass through a joint, it can cause pain, tingling, and muscle weakness, or it may interfere with joint movement.

The exact cause of ganglion cysts is unknown, but many times the cysts form after minor trauma to the wrist, such as a ligament sprain or tear. Activity and repetitive movements also play a role in their development. For example, if you play a sport that involves repetitive wrist movements, such as tennis, you may be more likely to develop ganglion cysts.

Anyone can be affected by ganglion cysts, but they are most common in people 15 to 40 years old. Women are more likely to be affected than men. These cysts are common in gymnasts and other athletes who repeatedly apply stress to the wrists.

Ganglion cysts at the end joint of a finger, known as mucous cysts, are typically associated with arthritis and are most common in women 40 to 70 years old.

To make a diagnosis, your NYU Langone doctor discusses your medical history and symptoms and performs a physical examination. He or she may ask you how long you have had the cyst and whether it changes in size or is painful. During the physical exam, your doctor may apply pressure to the hand and wrist to identify any tenderness. Because a ganglion cyst is filled with fluid, it is translucent. Your doctor may shine a light against the cyst to see whether light shines through.

Imaging tests may be necessary to make a diagnosis, including the following.

X-ray

An X-ray creates a clear picture of dense structures, like bone. Although ganglion cysts do not show up on X-rays, an X-ray can be used to rule out other conditions that cause discomfort and limit joint movement, such as arthritis or a bone tumor.

MRI Scan

Your doctor may order an MRI scan to better view the inside of the hand, wrist, ankle, or foot. MRI uses a magnetic field and sound waves to create two- or three-dimensional pictures of the inside of the body. Sometimes, an MRI is needed to find an occult ganglion cyst or to distinguish the cyst from other types of tumors. MRI can also identify ligament injuries associated with the cyst.

Ultrasound

Your doctor may use an ultrasound to evaluate the soft tissue of the hand, wrist, ankle, or foot. Ultrasound bounces high-frequency sound waves off parts of the body and captures the returning “echoes” as images. Ultrasound can help identify an occult ganglion cyst or rule out other types of tumors.

A cyst that causes no discomfort may not require treatment. Most ganglion cysts eventually go away on their own. However, if the cyst is painful or interferes with your activities, NYU Langone specialists offer several treatment options.