Definition and Overview
Ganglion cysts are benign or noncancerous lumps that grow out of a joint capsule or tendon’s lining. Although the exact reason why they occur is not known, it is believed that their growth is triggered when the tissue surrounding a tendon or joint bulges out of place.
Ganglion cysts are very common. They often develop near the tendons or joints of the hand and wrist. Rarely, they occur in the ankle region and knee area. In many cases, these cysts do not pose any significant medical threat nor require any form of treatment. However, if the cyst’s position is affecting certain ligaments or pushes on a nerve, it can make movements difficult and painful. Resting the affected joint and draining the cyst fluid can often alleviate such symptoms. In severe cases, open or arthroscopic surgery to remove the cyst and its stalk may be necessary.
Causes of Condition
Although ganglion cysts are very common, what causes them to form is not fully understood. However, doctors agree that the condition could be due to significant joint stress, which in severe cases can cause the joint capsule to break. When this happens, the synovial fluid leaks into the tissue that surrounds the joint. Subsequent reactions between the tissue and synovial fluid can cause the formation of a cystic wall. The fluid is then pumped into the cyst each time the wrist is moved. Some also believe that joint stress causes connective tissues to degenerate as well as stimulates the mesenchymal cells to secrete mucin, a glycoprotein constituent of mucus.
Another theory suggests that the condition occurs due to a flaw in the joint tendon or the capsule that covers it, which causes the connective tissue of the joint to bulge out.
Certain factors that can increase one’s risk of ganglion cysts are:
Gender and age - Ganglion cysts commonly occur in females aged between 15 and 40 years old.
Previous tendon or joint injury
Overuse - It is believed that the condition could be the result of the repetitive use of certain joints.
Osteoarthritis - Also called degenerative joint disease, osteoarthritis is the most common chronic condition of the joint.
In many cases, patients do not have other symptoms aside from a noticeable lump that does not move. Some, however, observe swelling and experience pain, which usually occurs when the cyst puts pressure on nerves that pass through a joint.
Who to See and Types of Treatments Available
A ganglion cyst is rarely a medical emergency unless it causes severe pain that prevents a person from doing certain activities. It can be diagnosed by a general practitioner (GP) or an orthopedist, a specialist in bones and joints. Normally, a review of the patient’s medical history and the physical examination of the lump (where a doctor shines a light through the cysts to see if it grows out of a joint or the lining of a tendon) are enough to make a diagnosis. If there are any doubts or if additional information is needed to rule out other medical conditions, the doctor may order magnetic resonance imaging (MRI) and an ultrasound; both are useful because they allow doctors to view the inside of the lump and detect its content. More importantly, they can detect if the mass is caused by an abnormality of a blood vessel or an artery. Rarely, an x-ray may also be performed if there is a reason to believe that the condition may be caused by a bone tumour or fracture.
Because ganglion cysts are not cancerous and do not pose any significant medical threat, treatment is not always necessary. If there are no symptoms, doctors usually advise a period of watchful waiting in which the patient is advised to monitor their condition and come back to the doctor if unusual changes occur. If needed, the affected joint can be immobilised using a splint or brace to allow it to rest and heal. Once the swelling subsides, the patient can perform specific exercises that can help strengthen and improve the joint’s range of motion.
If the patient continues to experience pain or if symptoms recur despite using a splint or brace, doctors often suggest aspiration in which the content of the cyst is drained using a needle. Although it offers immediate symptoms relief because it causes the lump to significantly reduce in size, needle aspiration has a high rate of recurrence because it does not remove the connection to the joint or tendon sheath. This makes the re-growth of another ganglion cyst highly likely.
When to consider surgical options?
Surgery is reserved as the last treatment option for ganglion cysts. It can be taken advantage of those who have tried all nonsurgical methods, including needle aspiration, but have not experienced long-lasting symptoms relief. It is also considered in cases where the cyst keeps on recurring. The goal of surgery is to remove the cyst and its stalk. It can be performed using the traditional open method where the surgeon creates an incision directly above the ganglion cyst. Another option is keyhole (arthroscopic) surgery, which uses several smaller holes where an arthroscope (a flexible tube with an attached light and camera) and other miniature surgical instruments are inserted. Both techniques are highly effective, but arthroscopic surgery reduces recovery time and the common risks of surgery, such as infection, scarring, and bleeding.
Ganglion cyst excision is often an outpatient procedure, which means that patients are allowed to go home the same day as long as there are no complications. Patients are then advised to limit hand and wrist movements to allow the wound to heal faster and avoid irritation.
Surgery to remove ganglion cysts is generally safe but it still carries risks of complications. A very small number of patients experience the following:
Pain, which can be managed with over-the-counter painkillers
Swelling at the removal site, which usually goes away with cold compress
Infection, which can be prevented by taking antibiotics and ensuring that the wound is clean
Chassat, R., Nourissat, G., Chaumeil, G., Dumontier, C. (2006, September). Arthroscopic treatment of dorsal ganglion cyst at the wrist. About 54 cases. Chirurgie de la Main, 25(3-4), 146-51. https://www.ncbi.nlm.nih.gov/pubmed/17175801
Frontera WR, et al. Hand and wrist ganglia. In: Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2015. http://www.clinicalkey.com.