Ganglion cysts of the foot and Ankle

Ganglion Cyst of the Foot and Ankle

Ganglion Cysts are a type of benign tumor or soft tissue mass that causes a bump, lump or enlargement on the foot. A cyst is an abnormal closed sac that is filled with either a fluid, gaseous, or semi-solid substance.  The Ganglion Cyst structure can best be described as being shaped like a water balloon.  They have a stalk type base (stem of balloon) which leads to the body of the cyst (balloon), which has a well demarcated membranous wall.  Ganglions are also known as "Bible Cysts".  This name comes from an old time treatment of the cyst by hitting it with the biggest book in the house, a bible.  Hitting the cyst causes the wall to rupture (popping of balloon) and the contents of the cyst can leak out.  Patients typically notice that the size of the mass/lump will change, getting larger and smaller.  This happens when the ganglion cyst wall spontaneously beaks or tears allowing the contents to leak out and the cyst/lump becomes smaller.  The defect in the cyst wall heals and refills with ganglionic fluid and then enlarges again.

Ganglion Appearance:

 A ganglion appears as a enlargement or bump, and may appear anywhere on the body but are commonly found on the hands, or feet (fig 1).  Ganglions are filled with a thick fluid whose consistency can vary from honey to a jam type consistency.  The actual size of the cyst can be deceiving.  Frequently a large portion of the cyst can't be visualized because its below the skin surface (similar to an iceberg) where its originating from a tendon or joint.

figure 1

Symptoms:

Typically patients will come to see the doctor out of concern over the a bump or lump which may or may not be painful.  Ganglions are not painful in and of themselves.  Ganglions become painful when they put pressure on vital structures or restrict motion, or become large enough that shoes begin to irritate them.  A common complaint from patients is nerve symptoms i.e. Burning, tingling or electrical sensations.  This occurs when the ganglion puts direct pressure on a sensory nerve.

Causes:

There is no definitive answer as to what causes a Ganglion.  The general consensus is that ganglions are due to trauma or irritation of a joint or tendon.  This can be either direct sudden trauma or more commonly minor repetitive trauma.  The repetitive or micro trauma can be as simple as constant shoe pressure over a tendon or repetitive irritation of a joint.

How do I know its a Ganglion?

Lumps and bumps on the foot can be caused by either a bony prominence or a soft tissue mass.  Prominences caused by bone are not freely movable in the surrounding tissue and have a firm hard consistency.  soft tissue masses that are not ganglion can sometimes be difficult to distinguish from a ganglion.  The location and "feel" of the mass can often give the doctor a diagnosis of ganglion with a high degree of certainty.  MRI's can also be helpful in identify if the enlargement is a ganglion or some other type of mass or bony prominence.  A doctor can also attempt to remove fluid from the a ganglion through a simple procedure called an aspiration.  To accomplish this a needle is inserted into the mass attached to a syringe.  When the plunger of the syringe is pulled back it draws fluid from the cyst into the syringe. (fig. 2)  This fluid can than be analyzed.

Treatment Options for Ganglions:

A Ganglion can be treated in two different ways:  Either by Aspiration(draining of the cyst) or by Surgical Excision. 

Aspiration of Ganglion:

(figure 2)

     As stated earlier aspiration is accomplished by inserting a needle and removing the contents.  This is done after injection of a local anesthetic to numb the area.  The procedure is simple, quick and the only discomfort is from the injection of anesthetic which is minor.  The procedure is typically performed in the office.   The patient can leave the office wearing their shoes and are able to drive or walk afterwards.   Some doctors may choose to inject a steroid (anti-inflammatory medicine) into the cyst after its been drained to help prevent return of the cyst.  Not all ganglions can be drained by aspiration and therefore need to be excised.

     Surgical Excision of Ganglion:

Surgical excision of a ganglion is done in a sterile operating room.  The patent is given a intravenous sedative and then the area where the cyst is located is numbed with a local anesthetic.  an incision made and the cyst is surgically removed.  There are obvious risks associated with surgery.  With excision of the ganglion there is a possibility of damage damage to nerves, blood vessels tendons and any other vital structures that may be encounter in the process of getting to and dissecting out the cyst.  Despite how ominous this may sound the complication rate with surgical excision is quite low.

There are several situations where I would recommend surgery for my patients:
- If the Ganglion is causing numbness, tingling, burning or significant pain.  This is due to pressure the mass on sensory nerves.
- If there is a question as to the mass is a ganglion or some other type of tumor.
- if the mass returns quickly or frequently after aspiration.
- If the Ganglion is causing difficulty wearing shoes

     With either treatment, recurrence of the cyst is possible.  However with aspiration the recurrence rate is much higher.  Aspiration is usually my first choice in treatment of a ganglion.  Its relatively painless, quick, and even if the ganglion returns the cyst can be aspirated again.   If unsuccessful, the mass can always be excised.