Ganglion cysts are sacs of synovial fluid that originate from the tendon sheaths or joints. They commonly occur in the wrist and fingers but can occur anywhere there is a joint or tendon sheath.
Ganglion cysts are thought to occur when the synovial membrane of the tendon sheath or joint herniates, forming a pouch. Synovial fluid flows from the tendon sheath or joint into the pouch, forming a cyst (a fluid-filled sac).
Presentation
Ganglion cysts can appear rapidly (over days) or gradually. Patients present with a visible and palpable lump. It is not usually painful. Rarely, they may compress nerves, leading to sensory or motor symptoms.
On examination, ganglion cysts:
- Range in size from 0.5 to 5cm or more (most are 2cm or less)
- Firm and non-tender on palpation
- Well-circumscribed
- Transilluminates (shining a torch into the cyst causes the whole lump to light up)
Diagnosis
Ganglion cysts are mostly diagnosed clinically, based on the history and examination findings.
X-rays will show normal bones and joints (unless there are co-existing conditions).
Ultrasound can help confirm the diagnosis and exclude other causes of lumps.
Management
Ganglion cysts may be managed conservatively, without any intervention. 40-50% of cysts will resolve spontaneously, but this can take several years.
Active management options for ganglion cysts are:
- Needle aspiration (draining the cyst by aspirating the fluid with a needle)
- Surgical excision (open or endoscopic removing the cyst, usually under local anaesthetic)
Needle aspiration has a high rate of recurrence (50% or more).
Surgical excision involves removing the entire cyst and the affected part of the joint capsule or tendon sheath. Therefore, the recurrence rate is low. However, there is a risk of complications, such as infection and scarring.
Last updated August 2021