Gangions are the most common cause of a bump or mass around the wrist. These are 100% benign. They’re simply herniations of fluid from an underlying joint caused by a weakness in its ligaments. When there is damage to the ligaments or the joint capsule (balloon) around the joint, an area of weakness is created. The joint fluid that lubricates your joint can herniate through this area of weakness, forming a fluid-filled cyst called a ganglion. A one-way valve mechanism forms from the joint lining and prevents the fluid from going back into the wrist, trapping it in the cyst. Because they come from your joints, ganglions can sometimes get bigger during periods of heavy activity and get smaller during periods of rest.
It’s important to understand that not every bump is a ganglion. However, ganglions can be diagnosed fairly easily. Ganglions on the back of the wrist can be aspirated in the clinic. This involves numbing the overlying skin with a small needle and some lidocaine, similar to the novocaine used by dentists. A larger needle is then placed through the numbed skin to draw out the gelatinous fluid inside. This causes the ganglion to disappear or at least decrease in size, and in 1/3-1/2 of cases provides a permanent cure. Sometimes the ganglion has separations and subcompartments within it that make it difficult to fully aspirate. These ganglions with multiple compartments have a lower rate of cure by aspiration.
Ganglions on the palmar surface of the wrist are not usually aspirated. They are usually intertwined with the radial artery, and a large needle could injure the artery or the nearby median nerve. Ganglions can also occur in the fingers, in unusual locations about the wrist, or over other joints.
Once a ganglion is diagnosed, it does not have to be removed. Except in rare cases where it presses directly on a nerve, it will not cause any damage. However, ganglions can cause pain with activity and many people want them removed because they often look unsightly.
Ganglion excision surgery is quick and highly effective. While the literature quotes a 5-10% rate of recurrence for ganglions on the back of the wrist and a 10-20% rate of recurrence for ganglions on the palmar surface of the wrist, as far as I know, I’ve never had a wrist ganglion recur in an adult after I have personally removed it. The key is to remove enough of the joint capsule (the balloon around the joint) that the capsule can’t scar back to itself and so it remains partially open. This prevents the reformation of a one-way valve and creates a permanent “two-way valve” which prevents the recurrence of the ganglion.
After surgery, activity is fairly unrestricted. The wound should be kept clean and dry for 4 days, at which time the dressing can be removed and the wound can get wet in the shower and pat dry. A band-aid can be placed over it. The wound should not be submerged under water for two weeks.
Ganglions in children have a much higher recurrence rate following both aspiration and surgical removal. Strong consideration should be given to not operating in children until they’ve reached “skeletal maturity”, around the age of 16 years. However, the mass should be evaluated by a hand surgeon to ensure that it is, in fact, a ganglion and not another type of lesion.