Ganglions are among the most common tumors of the hand and wrist.  For the most part, they are asymptomatic masses that are primarily cosmetic rather than functional disturbances. In most instances, observation is the only management necessary. However, some ganglions can exert a mass effect on nearby structures, such as arteries, veins, tendons, and nerves. The impingement of such structures can cause pain, triggering of tendons, and vascular compromise. In these instances, the patient often seeks surgical attention. [2, 3, 4, 5, 6]
People have been seeking treatment for ganglions for many centuries. Historically, treatment consisted of crushing the ganglion with a heavy object (eg, a Bible). Often, a firm strike with a heavy object was all that was needed to cure the patient. Now, simple observation, aspiration, and surgical excision are the treatment modalities of choice. It should be kept in mind that each type of ganglion can cause local symptoms, depending on its anatomic location.
For patient education resources, see Ganglion Cyst and Carpal Tunnel Syndrome.
Hippocrates described ganglions as "knots of tissue containing mucoid flesh." Since this description, several hypotheses have been proposed, including the following:
Synovial herniation or rupture through the tendon sheath (Eller, 1746)
Synovial dermoid or rest due to "arthrogenesis blastoma cell nests" or embryonic periarticular tissue (Hoeftman, 1876)
New growths from synovial membranes (Henle, 1847)
Modifications of bursae or degenerative cysts (Vogt, 1881)
The theory of mucoid degeneration offered by Ledderhose in 1893 was widely accepted. Green , however, replaced this theory with one based on microtrauma and hyaluronic acid production.  The latter theory postulated that local tissue trauma or irritation causes production of hyaluronic acid at the synovial-capsular interface. The hyaluronic acid creates small mucin lakes that coalesce into subcutaneous cysts with stalks or ganglions.
The etiology of ganglions is unknown. Theories include mucoid degeneration and trauma. Some patients (<10%) recall minor or major trauma to the area before the development of the mass. No known occupational risk factors exist. Mucous cysts and some other ganglions are associated with degenerative joint disease.
Ganglions in general represent 50-70% of all soft-tissue tumors of the hand and wrist. The prevalence in women is three times that in men. Most ganglions occur in persons aged 10-40 years, with a range from childhood to the ninth decade of life.
These tumors may occur in a variety of locations. Mucous cysts are ganglions of the distal interphalangeal (DIP) joint that occur primarily in persons aged 40-70 years. These also occur more commonly in females than in males.
Given that ganglions are benign lesions, the overall prognosis is excellent with open surgical treatment. Recurrence rates of 10-15% are typically reported. Excision of the cyst with a small ring of capsule has been shown to reduce the recurrence to 4% when compared with resection of the cyst alone (13-40%).
Osterman and Raphael found that arthroscopic treatment was also safe and reliable.  They had recurrences equal to those reported with open procedures. Arthroscopic resection also resulted in smaller surgical scars.
Sanders reported dramatic improvement of function and relief of pain in selected patients who had a suspected occult ganglion.