Ganglion cysts are the most common mass or lump in the hand. They are not cancerous and, in most cases, are harmless. They occur in various locations, but most frequently develop on the back of the wrist.
These fluid-filled cysts can quickly appear, disappear, and change size. Many ganglion cysts do not require treatment. However, if the cyst is painful, interferes with function, or has an unacceptable appearance, there are several treatment options available.
Ganglion cysts can develop in several of the joints in the hand and wrist, including both the top and underside of the wrist, as well as the end joint of a finger, and at the base of a finger. They vary in size, and in many cases, grow larger with increased wrist activity. With rest, the lump typically becomes smaller.
It is not known what triggers the formation of a ganglion. They are most common in younger people between the ages of 15 and 40 years, and women are more likely to be affected than men. These cysts are also common among gymnasts, who repeatedly apply stress to the wrist.
Ganglion cysts that develop at the end joint of a finger — also known as mucous cysts — are typically associated with arthritis in the finger joint, and are more common in women between the ages of 40 and 70 years.
Most ganglions form a visible lump, however, smaller ganglions can remain hidden under the skin (occult ganglions). Although many ganglions produce no other symptoms, if a cyst puts pressure on the nerves that pass through the joint, it can cause pain, tingling, and muscle weakness.
Large cysts, even if they are not painful, can cause concerns about appearance.
During the initial appointment, your doctor will discuss your medical history and symptoms. He or she may ask you how long you have had the ganglion, whether it changes in size, and whether it is painful.
Pressure may be applied to identify any tenderness. Because a ganglion is filled with fluid, it is translucent. Your doctor may shine a penlight up to the cyst to see whether light shines through.
X-rays. These tests create clear pictures of dense structures, like bone. Although x-rays will not show a ganglion cyst, they can be used to rule out other conditions, such as arthritis or a bone tumor.
Magnetic resonance imaging (MRI) scans or ultrasounds. These imaging tests can better show soft tissues like a ganglion. Sometimes, an MRI or ultrasound is needed to find an occult ganglion that is not visible, or to distinguish the cyst from other tumors.