Ganglions on the foot are much more common than many people can tell you, and they tend to arrive just in time for the worst possible occasion; for example, right when you were just trying out your new jogging shoes.
And these soft, fluid-filled lumps develop really quickly so it can be alarming when they first appear.
But the good news is, although they can be painful and sometimes frightening, a foot ganglion cyst is almost always benign.
This article covers all the details – what they are, why they develop, symptoms to watch out for, and what treatment options are available including the options of no treatment and surgery – in detail and in the order to best explain it.
What Are Ganglions on the Foot?
A ganglion cyst is a benign, fluid containing lump that is found near to joints or tendons.
The cyst is filled with thick, gel-like liquid called synovial fluid, the body’s lubricant for the joints.
On the foot these cysts will commonly attach to the joint capsule or the tendon sheath. The cysts themselves can be the size of a pea or the size of a grape.
Most are no problem, but because they are on the foot, they have a tendency to get caught on the heel or are prone to rubbing on shoes; which can be bloody annoying.
Common sites and presentation
On the foot specifically most commonly they can be seen on the dorsum (top of foot) around the ankle joint or back along the small toe tendons.
They may also appear on the bottom of the foot. This can sometimes cause walking to feel like there’s a stone stuck underneath.
The lump always feels soft, smooth and round, and a bit soft, rather than solid (e.g. bone).
One feature is the size; it can change.
A cyst has the potential to be more prominent after activity and less prominent after rest.
Others, wake up one morning and the bump has gone away, and then a few weeks later it comes back.
That is precisely what defines a ganglion cyst.
Symptoms and When They Cause Problems
Not all ganglions on the foot ache.
Many can identify a lump and experience no symptoms other than mild pressure while wearing a closed shoe.
But the point about the place really does count here.
A cyst that lie on top of the nerve or under a constrictive shoe can evoke a acute burning sharp pain. If a cyste is horizontal to the joint it can cause a dull ache aggravate by walking or standing for long periods.
Another consideration is swelling and/or redness about the ankle, especially if the cyst opens into the ankle joint.
When is Medical Attention for a Lump Needed
Most ganglion cysts don’t call for emergency assessment, yet the following indications highlight the importance of quickly scheduling an appointment with a podiatrist or doctor.
Significant increase in size over a few weeks; Paresthesia/numb toes (possible nerve compression); intractable (unresponsive to rest) pain; a hard, fixed lump to deeper tissue; these are all red flags.
A ganglion should glide slightly and if it does not, then this is something to look into.
Other skin changes over the lump such as erythema, warmth or skin retraction may suggest a diagnosis other than cyst.
Having a professional assessment for these problems isn’t being paranoid; it’s clever.
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Causes and Risk factors Proposed
There is no known underlying cause and aetiology of the ganglion but it is believed to be due to inflammation or micro-trauma occurring in a joint capsule or tendon sheath.
Stress repeatedly applied results in tissue breakdown which results in flow of synovial fluid escaping and ponding into a sac.
These often occur in people who are on their feet for extended periods, athletes who through repetitive movements exert strain through the foot and ankle and people with pre-existing joint conditions such as osteoarthritis.
Subjects are more affected by females than males statistically (but there is not really a reason for this).
Why may ganglions appear and disappear
Fluctuation of ganglion pathology is one of the main reasons for uncertainty felt by the general population.
The fluid within the cyst can temporarily move back into the joint space, temporarily reducing the lump.
Whether due to activity, footwear, even hydration, the size of the cyst can vary from day to day.
This old folk story of “smashing” ganglions with heavy books was once common practice, i.e. through forcefully spreading the fluid.
Today we wouldn’t recommend that method (it is very painful and the cyst tends to come back), but it does show how easily the fluid is redistributed:
Relapse is really common even after the patient has been appropriately treated.
Diagnosis and Differentiating from other lumps
Within the history the handling of the lump probably holds the key to the diagnosis. A doctor may be able to identify a ganglion even without the use of any other investigations.
The usual test is done by shining a small torch through the lump-if we consider that the fluid inside of it is clear, then the light will shine through-the transillumination!
A lump of solid structure, such as a lipoma or bony mass, will not let the light pass through.
That said, when it comes to a cyst in an uncommon place, or one that doesn’t feel the right way, a clinical exam isn’t always conclusive.
Imaging and Differential diagnosis
Ultrasound is the main modality used to confirm the presence of a ganglion on the foot.
It’s quick, inexpensive and can provide a very clear indication whether the lump is cystic or solid.
MRI presents more detail and may be requested when the diagnosis is uncertain or if the cyst is thought to be pressing on vital structures.
Several conditions can potentially simulate a ganglion. These include lipomas (soft fatty lumps), bursae (fluid filled cushions), fibrous tumours and even bony protrusions from arthritis.
Making the right diagnosis makes a difference because treatment varies from one disorder to another.
Treatment Options for Ganglions on the Foot
There are several treatment options if treatment is required to help shrink and resolve the cyst. Just to reiterate, small painless syndromes that are not causing restrictions in daily activities may not need some form of treatment.
Watchful waiting is a perfectly valid option and indeed some cysts will spontaneously disappear given enough time months to years.
Treatment is usually indicated when the pain is severe, or the cyst is hindering normal activity.
Conservative care and Shoe modifications
For fairly mild cases: the initial management is aimed at reducing irritation.
It was found that changing to shoes with wider toe boxes or open toe shoes helped offload the cyst. This often gave significant relief.
Soft padding or foam donut pads around (not over) the lump can postion pressure so that it is shared.
Rest and ice are also able to subdue inflammation when they are experiencing the flare effect.
These modifications won’t remove the cyst, but they can turn it into nothing of concern on a daily basis.
Aspiration, surgery and recurrence
In cases where conservative treatment has failed aspiration, or removal using a needle, is often the next step.
It is carried out as a clinic, instantly decreases size, and has little risk.
The negative is a recurrence rate of about 50 percent or more.
Surgical excision—take the cyst out and leave the root attachment to the joint or the tendon, this decreases the likelihood but doesn’t totally prevent a recurrence.
Recurrence rate is also as high as 10 to 20 percent even with surgery so it is good to let parents know of this before.