They are benign cysts that often appear on the hand and / or wrist.

Signals and symptons

Synovial cysts are characterized by:

Localization: They often develop along the tendons or over joints of the hand and wrist. The most common are on the back of the wrist, and their appearance on the palmar face, at the base of the fingers or on the back of their last joint is also common.

Shape and size: They are usually round or oval and usually do not exceed 2.5 cm. Some are so small that it is not possible to identify without tests such as ultrasound or magnetic resonance imaging.

Pain: Although they may be pain-causing they are often painless.


It is not known exactly what causes the cyst. It originates from a joint or the path of a tendon and resembles a fluid pocket (a thick fluid that acts as a lubricant) that appears to have leaked from its usual location within the joint or tendon sheath.

Risk factors

There are factors that may increase the risk of developing a synovial cyst:

Gender and age: Although they may appear in any gender or age, they are more common in women between 20 and 40 years.

Arthrosis: Arthrosis involving the last joint of the fingers can lead to the development of cysts near the beginning of the nail.

Tendon or joint injuries: Tendons or joints that have suffered injuries in the past are more likely to develop cysts


The diagnosis is made by medical observation. In order to confirm the liquid filling of the cyst, a light may be shed on the cyst and the light may spread, which is not the case if the lesion in question is not liquid but solid.

If the cyst is associated with other medical conditions, such as arthrosis or ligament injuries, additional tests may be required: rx, ultrasound or magnetic resonance imaging. Ultrasound and resonance also make it possible to identify small cysts that are not visible to the naked eye but may cause wrist pain.


Synovial cysts are often painless, requiring no treatment. In this situation, only vigilance is advised in order to understand the impairment in daily activities.

If the cyst is painful or interferes with joint movement, treatment options are:

Immobilization:  Performing movements, especially associated with force, leads to increased cyst. Placement of a resting splint leads to immobilization of the affected area and may allow the reduction of the cyst and the alleviation of pain. Immobilization is not, however, a valid option if complaints recur.

Aspiration: Cyst can be drained by needle aspiration. It may promote pain relief but the procedure itself is uncomfortable and the risk of recurrence of the cyst is high.

Surgery:  If complaints of pain and interference with movement persist, surgery is recommended. In surgery the cyst is removed. In cysts affecting the wrist joint, surgical removal can be done openly, ie with an incision of about 2 cm over the cyst by removing the fluid pouch, or arthroscopically, where about 2 to 4 incisions of the wrist are made. 5 mm through which instruments are placed to allow the cyst to be seen and removed (this last surgical option has the advantage of leaving a smaller scar and a faster postoperative recovery period). In other cysts affecting the hand, excision is performed by open surgery, with incision over the cyst.