Ganglion Cyst

A ganglion cyst is a fluid-filled sac that arises from a joint capsule or tendon sheath, most commonly on the back of the wrist, though they can occur at the front of the wrist, the base of the fingers, or the fingertip joint. They are the most common soft tissue lump found in the hand and wrist.

Ganglion cysts are entirely benign, meaning they are not cancerous and carry no risk of becoming so. Their size can fluctuate over time, sometimes appearing to disappear and then return, and this variability is a normal feature of the condition rather than a cause for concern.

The exact cause of ganglion cysts is not fully understood. They are thought to arise when fluid from a nearby joint or tendon sheath leaks out and collects in a sac, sometimes related to minor, unnoticed wear or irritation of the joint or tendon lining. In many cases there is no clear trigger at all, and they can occur in otherwise healthy joints.

Common features of a ganglion cyst include:

• A visible or palpable lump, most often on the back of the wrist
• A lump that may change in size over time, or seem to come and go
• Mild ache or discomfort, particularly with wrist extension or repetitive activity, though many cysts are entirely painless
• Occasionally, tingling or altered sensation if the cyst is pressing on a nearby nerve

The diagnosis is usually straightforward based on the appearance and location of the lump, though imaging can be used if there is any uncertainty.

Assessment usually confirms the diagnosis based on examination alone, given the characteristic appearance and location of ganglion cysts. Imaging such as ultrasound can be used if the diagnosis is uncertain or to check the cyst's relationship to nearby structures.

If the cyst is painless and not enlarging, observation is a reasonable approach, as many ganglion cysts settle without any treatment. For symptomatic cysts, aspiration, draining the fluid with a needle, can provide relief, though the cyst returns in a meaningful proportion of cases.

For persistent or troublesome cysts, surgical excision removes the cyst along with its attachment to the underlying joint or tendon sheath, which lowers, though does not eliminate, the chance of recurrence.

Ganglion cysts are benign and many resolve on their own over time without any treatment. Recurrence after either aspiration or surgical removal is a recognised possibility, with aspiration carrying a higher chance of the cyst returning than surgical excision. Overall, the condition is not dangerous and does not affect long-term joint health.

Ganglion cysts are common, benign lumps at the wrist or hand and are not a sign of anything more serious. Many can simply be watched, while aspiration or surgical removal are available for cysts that are painful, enlarging or affecting hand function. A new lump at the wrist or hand is worth having assessed to confirm the diagnosis, even though ganglion cysts themselves are not dangerous.