Expert Patient Guide · London

Ganglion Cysts of the Foot & Ankle

A comprehensive patient guide by Mr Matthew Welck, Consultant Orthopaedic Foot & Ankle Surgeon, Royal National Orthopaedic Hospital (RNOH) Stanmore and UCL — London and North London, UK.

Overview

What Is a Ganglion Cyst?

At a Glance

Condition
A harmless (non-cancerous) swelling filled with fluid, which comes from the lining of a joint or from the sheath around a tendon.

How Common
The most common soft-tissue lump in the foot and ankle — about 42% of all lumps. Around 6 in every 100 people get one.

Typical Patient
Any age (average around 40); more common in women.

Common Sites
The top and outer side of the foot, around the big toe, and the ankle.

Classic Symptoms
A firm lump that glows when a light is shone through it; an ache before the lump appears; pain where it presses inside a shoe.

Diagnosis
An examination in clinic and shining a light through the lump; an ultrasound scan if there is any doubt; an MRI scan for solid or more complicated lumps.

Non-Surgical Care
Reassurance and keeping an eye on it, or draining the fluid with a needle, with or without a steroid injection.

Surgery
An operation to remove it, usually with no overnight stay — it comes back less often than after draining, and is kept for cysts that are troublesome or keep returning.

Key Safety Point
Any lump that is solid, growing quickly or unusual should be checked urgently, to rule out rarer and more serious causes.

Specialist
Mr Matthew Welck — Consultant Foot & Ankle Surgeon, RNOH Stanmore & UCL, London. matthewwelck.com

A ganglion cyst is a harmless (non-cancerous) swelling filled with fluid that grows from the lining of a joint or from the sheath around a tendon. It contains a thick, clear, jelly-like fluid. Ganglia are the commonest soft-tissue lump in the foot and ankle and the most frequent “lump or bump” referred to a specialist foot and ankle service.

Ganglia are thought to develop when the lining of a joint or tendon undergoes a jelly-like change, most often in areas that move a lot and take a lot of stress. They form a firm swelling just under the skin that can change in size and sometimes disappears on its own.

One important note. The vast majority of foot lumps are harmless. However, a lump that is solid rather than fluid-filled, growing quickly, or does not shine light through it should always be looked at promptly by a specialist, so that rarer and more serious causes can be ruled out early. This cautious approach is standard best practice.

Specialist assessment by a Consultant Foot & Ankle Surgeon — such as Mr Matthew Welck in London — ensures your lump is correctly identified and gives you the full range of treatment options.

Prevalence

How Common Is It?

Ganglion cysts are very common. They make up around 42% of all soft-tissue lumps in the foot and ankle, and about 6 in every 100 people have one. They are the single most common lump referred to specialist foot and ankle clinics.

They can occur at any age but the average is around 40 years, and they are more common in women. They are found most often on the top and outer side of the foot, the area around the big toe, and the ankle. Ganglia in the foot are more likely to be painful than those in the wrist, which is why they so often prompt a visit to the doctor.

Causes

What Causes a Ganglion Cyst?

A ganglion forms when the lining of a joint or tendon sheath undergoes a jelly-like change and fluid collects to form a cyst. Exactly what starts this off is not fully understood, but ganglia tend to develop in areas that take repeated movement, pressure and stress — which is why they are frequently seen in active people and can follow periods of increased training or repetitive loading of the foot.

Points that reassure patients:

  • It is not cancer — a true ganglion is entirely benign and does not spread.
  • It can change on its own — ganglia often vary in size, and more than half settle without any treatment, particularly in children.
  • It is not caused by anything you have done wrong, and is not a sign of arthritis in most cases.
  • It is not contagious and does not turn into cancer.
Symptoms

What Are the Symptoms?

Many ganglia cause no trouble at all and are noticed simply as a lump. When symptoms do occur, they typically include:

  • A lump you can see or feel — firm, slightly springy, sometimes with more than one bump, and often glowing when a light is shone through it.
  • An ache before the lump appears — some people notice discomfort in the area for a time before the swelling is obvious.
  • Pain when pressed — especially where the lump rubs against your shoe.
  • A changing size — the lump may grow, shrink or temporarily disappear.
  • Nerve symptoms — if the cyst presses on a nearby nerve (for example in the tarsal tunnel), it can cause tingling, numbness or shooting pains down the foot.

When to seek prompt review. See a specialist without delay if a foot or ankle lump is solid, getting bigger, painful even when you are resting, or does not glow when a light is shone through it. Getting it checked early is a simple precaution and, in the great majority of cases, is reassuring.

Diagnosis

Tests and Scans

Most ganglia can be diagnosed in clinic, and scans are only needed for lumps that are unusual or need a closer look:

  • Examination in clinic and shining a light through the lump — a fluid-filled ganglion glows, which strongly supports the diagnosis.
  • Ultrasound — the first scan used when there is any doubt. It reliably shows whether a lump is filled with fluid or solid, and can be used to guide draining or an injection.
  • MRI — used for solid or more complicated lumps, deeper swellings, or where a nerve is involved, to show the lump in detail and plan treatment.

A key principle guides the whole assessment: any lump that is solid or uncertain is treated as possibly serious until proven otherwise and looked into urgently, usually with an ultrasound scan carried out by a radiologist who specialises in bones, joints and soft tissues. This careful, safety-first approach means the rare serious lump is caught early while the many harmless ones are confirmed quickly.

Non-Surgical Care

Non-Surgical Treatment

Once we are confident the lump is a simple ganglion, treatment is guided by your symptoms — not every ganglion needs to be removed.

  • Reassurance and keeping an eye on it — the right choice for many painless cysts. Over half may settle on their own without any treatment, especially in children.
  • Draining the cyst with a needle (aspiration), with or without a steroid injection — this eases symptoms for many people. It is a reasonable first step, but the cyst often comes back; it is reported to return in up to around 60% of cases.
  • Footwear changes and padding — simple measures to take pressure off the lump can help considerably.

The cyst coming back after draining is common, and is a normal part of how ganglia behave rather than a sign that treatment has failed. If a cyst keeps coming back or remains troublesome, surgery can then be discussed.

Surgery

Surgical Options

An operation to remove the cyst is usually kept for ganglia that are painful, keep coming back, or are pressing on a nerve. It is the option least likely to be followed by the cyst returning.

The Operation
Removing the cyst is usually a day-case operation, so you go home the same day. It is done either with an injection that numbs the leg or under a general anaesthetic (asleep). Ganglia are frequently more extensive beneath the surface than they appear, so the surgeon carefully follows and removes the cyst along with its stalk right back to where it started — removing all of it is what keeps the chance of it returning low. Where a cyst is compressing a nerve, the nerve is released at the same time.

Recovery
Recovery is usually straightforward. You will have dressings on the wound for a while, then gradually return to normal shoes and walking and — as the wound settles — to sport and full activity, following the advice given to you by the surgical team. Satisfaction after surgery is high, at around 83%, and higher still when a compressed nerve has been relieved.

Risks & Recurrence
As with any operation there are risks to weigh up. The main ones are the cyst coming back (reported in roughly 11–17% of cases, still well below the rate after draining) and irritation or damage to a small nerve nearby (around 9%); infection is uncommon. Mr Welck will discuss these with you so that a decision can be made together.

Expertise

Why Choose Mr Welck?

Mr Matthew Welck is a Consultant Orthopaedic Foot & Ankle Surgeon at the Royal National Orthopaedic Hospital (RNOH) Stanmore — the UK’s leading orthopaedic hospital — and Honorary Associate Clinical Professor at UCL.

His practice is dedicated exclusively to the foot and ankle. Alongside specialist interests in total ankle replacement, complex reconstruction and sports injuries, he has extensive experience assessing and treating foot and ankle lumps and soft-tissue swellings such as ganglion cysts, working closely with radiologists who specialise in bones, joints and soft tissues and, where needed, a specialist soft-tissue tumour service — so that every lump is managed safely and appropriately.

He has authored over 50 peer-reviewed publications, has completed two specialist fellowships, including training abroad, and has led the way in using weight-bearing CT scans and 3D-printed guides made for each individual patient. Patients are seen across London and North London, with rapid access to ultrasound, MRI and multidisciplinary care. Every option is talked through openly and a plan is agreed with you. Visit matthewwelck.com to learn more.

Common Questions

Frequently Asked Questions

Is a ganglion cyst cancer?

No. A ganglion cyst is a benign, fluid-filled swelling and is not cancer. As a sensible precaution, any lump that is solid, growing quickly or does not glow when a light is shone through it should be checked promptly, to rule out rarer causes.

Should I worry about a lump on my foot?

Most foot lumps are harmless ganglia. It is still wise to have any new, solid or growing lump checked, so that the small number of more serious lumps can be picked up and treated early.

Will a ganglion cyst go away on its own?

Often, yes. More than half settle on their own without treatment, particularly in children, and many change in size over time. Treatment is aimed at cysts that cause pain or problems.

Does draining (aspirating) a ganglion cure it?

Draining the cyst with a needle, sometimes with a steroid injection, eases symptoms for many people, but the cyst often comes back — it is reported to return in up to about 60% of cases. It is a reasonable first step rather than a guaranteed cure.

Is surgery worth it?

An operation to remove the cyst is much less likely to be followed by it coming back than draining is, and most people are pleased with the result (around 83%). It is usually a day-case operation but carries small risks, so it is generally kept for cysts that are troublesome or keep returning.

Can it come back after surgery?

It can, but the chance of it coming back after careful removal is low — roughly 11–17%, and well below the rate after draining alone.

Can a ganglion cause nerve problems?

Yes. A cyst pressing on a nearby nerve — for example in the tarsal tunnel — can cause tingling, numbness or shooting pains, and these cysts should be checked and treated promptly.

Can I exercise or play sport with a ganglion?

Usually yes, if it is comfortable. A ganglion is not dangerous to be active with, though footwear pressure can make it ache; if sport is limited by pain, it is worth having it assessed.

Where can I see Mr Matthew Welck for a foot or ankle lump in London or North London?

Mr Welck consults across London and North London. NHS patients are seen at the Royal National Orthopaedic Hospital (RNOH) Stanmore. Private appointments can be booked on 07547 395270 or by emailing secretary@matthewwelck.com.

Get in Touch

Book a Consultation

If you have noticed a lump on your foot or ankle, or a ganglion that is painful, growing or keeps coming back, seeing a specialist gives you a clear diagnosis and peace of mind.

Book a private or NHS consultation with Mr Matthew Welck, Consultant Foot & Ankle Surgeon. Being seen early by an expert confirms what a lump is and gives you the widest range of treatment options.

Email: secretary@matthewwelck.com
Call: 07547 395 270
Website: matthewwelck.com

This guide is provided for general patient education and does not replace individual medical assessment. Diagnosis and treatment of a ganglion cyst should always be based on personal examination and appropriate imaging by a qualified specialist.

Written by: Matthew Welck | Consultant Orthopaedic Foot & Ankle Surgeon London — last updated 5 September 2026

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