A ganglion cyst appears as a fluid enclosed bump usually around a joint or tendon sheath in the hand, wrist, or foot.
Ganglion cysts are the most common soft tissue mass of the hand and wrist (55 per 100,000 of population per year.) They occur in a 3 to 1 female to male ratio. These cysts can arise at any age with the majority presenting between the second and fourth decades (60-70%). There does not appear to be any relationship between ganglion cysts and dominant hand or occupation.
Currently, no single theory adequately explains what causes ganglion cysts to appear. Most modern theories are based on the belief that ganglion cysts arise from within the connective tissue. Some theories:
Repetitive trauma stimulates hyaluronic acid/mucin production by modified synovial cells at the synovial-capsular interface. Mucin dissects along the attached ligament and capsule to form capsular ducts. These ducts, in turn, act as valve-like structure that leads to the formation of mucin lakes. The mucin in the ducts and lakes accumulates to eventually form a ganglion cyst.
Mucinous degeneration results in cyst formation due to chronic damage. Later degeneration of the joint capsule results in cyst communication with the joint. Ganglion cysts may arise due to herniations of synovial tissue from the joints.
The vast majority of ganglion cysts arise as small painless bumps ranging in size from 1 to 3 cm. Most have a firm or rubbery consistency and are mobile. Occasionally these cysts can be symptomatic. The most common presenting symptoms include:
Typically the pain is dull and persistent and worse at the extremes of wrist motion. More frequently, pain is associated with dorsal ganglion and smaller ganglion size.
Sometimes a ganglion puts pressure on the nerves that pass near the joint; this may weaken hand strength, affect joint motion, or cause tingling in the fingers, hand, or forearm.
Appearance and location is often sufficient to diagnose a ganglion cyst. In addition, the cyst will trans-illuminate with a flashlight on physical exam.
Cyst fluid may be removed and examined to confirm the diagnosis
Often reserved for cases in which there is suspicion for other etiologies such as osteoarthritis, bone spurs, bone tumors, or fractures. However, x-rays can also be used to determine cyst related damage to wrist bones.
MRI or Ultrasound
Rarely used for the purpose of diagnosing ganglion cysts.
You must take into consideration that most ganglions will disappear without any treatment and often return despite treatment. If the cyst is not painful or interfering with function, often all that is needed is education, reassurance, and expectant management. More aggressive treatment is indicated if a ganglion becomes symptomatic, infected, or is affecting adjacent bones or ligaments. Treatment options include:
A large, 16 gauge needle is used to aspirate the cyst. This is rarely a permanent solution. In one study with 34 patients, 59% of cysts reoccurred within three months.
Aspiration with a Steroid Injection
Most commonly used approach. Thought to be more effective than aspiration alone. However, studies have shown cure rates ranging from 57-79%
Injection of Hyaluronidase followed by Aspiration:
95% cure rate at 6 months
Aspiration and instillation of steroid
With the prior use of hyaluronidase (87% cure at 2 years compared to 57% without hyaluronidase)
Open procedure versus less invasive arthroscopic approach. The goal is to remove the ganglion sac and connecting tissue. Has a 5 to 10% recurrence rate.