Synovial Cyst of Wrist

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1- Introduction

2- Anatomical Overview

3- Causes

4- Treatment 


Sometimes a nontender cystic swelling appears on the hand, most commonly on the dorsum of the wrist. Usually the cyst is the size of a small grape, but it varies and may be as large as a plum. The thin-walled cyst contains clear mucinous fluid. The cause of the cyst is unknown, but it may result from
mucoid degeneration. Flexion of the wrist makes the cyst enlarge, and it may be painful.
© image from moore clinically oriented anatomy

Anatomical Overview

Synovial cysts are close to and often communicate with the synovial sheaths on the dorsum of the wrist (. The distal attachment of the ECRB tendon to the base of the 3rd metacarpal is another common site for such a cyst. A cystic swelling of the common flexor synovial sheath on the anterior aspect of the wrist can enlarge enough to produce compression of the median nerve by narrowing the carpal tunnel (carpal tunnel syndrome).


  • The exact cause of synovial cysts is not well understood, but they may be related to:

    • Joint or tendon irritation
    • Degeneration of tissues
    • Repetitive stress or injury to the wrist
    • Underlying conditions like arthritis


  • Observation: If the cyst is not causing pain or limiting movement, a watch-and-wait approach may be taken.
  • Immobilization: Wearing a wrist brace or splint can help reduce cyst size by limiting movement and stress on the joint.
  • Aspiration: A needle is used to drain the fluid from the cyst. This procedure is often guided by ultrasound. However, cysts may recur after aspiration.
  • Surgery: If conservative treatments fail or the cyst recurs, surgical removal may be necessary. This procedure is typically performed on an outpatient basis.
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