Mucous Cyst Finger

Primarily affecting the distal interphalangeal joint, a mucous cyst finger condition causes a small, fluid-filled sac to develop close to the nail bed.

What is a mucous cyst finger?

Also known as a myxoid cyst or ganglion, a digital mucous cyst is a relatively small growth which affects the tips of the fingers. Usually, a mucous cyst finger issue affects the top part of the finger, between the distal interphalangeal joint and the nail bed itself.

In most cases, a digital mucous cyst occurs on just one finger and may be situated on one side of the digit, rather than in the center of the finger itself. Although they can occur on either hand, a mucous cyst finger is more likely to develop on the patient’s dominant hand.

What are the symptoms of mucous cyst finger?

When a digital mucous cyst forms, individuals may notice a small lump on their finger but they may not report any other symptoms. In some cases, however, a myxoid cyst can cause a number of symptoms, such as:

  • Swelling
  • Pain
  • Restricted movement of the finger
  • Clear discharge from the cyst
  • Changes to the nail

As a distal mucous cyst is fluid-filled, it may take on the appearance of a blister at first. Depending on the amount of fluid in the cyst, the area may swell quite considerably and mucous cysts on the finger are usually fairly noticeable. Whilst some patients do not experience pain as a result of mucous cysts, they can be very painful for other individuals. Often, pain is accompanied by restricted movement of the distal interphalangeal joint on the affected finger.

As these type of cysts form near the nail bed, they can often cause damage to the growth plate of the nail and the nail itself. Due to this, the nail on the affected finger may split or have a series of grooves along it.

On occasion, the cyst may produce a thick, clear fluid. If the cyst bursts, this fluid may leak on to the surrounding skin, whilst some fluid may remain in the cyst itself.

What causes mucous cyst finger?

There are thought to be two main causes of mucous cysts affecting the fingers:

  • Degenerative changes to the joints
  • Excess production of hyaluronic acid

As people age, their joints can change or succumb to wear and tear. When this happens to the distal interphalangeal joint, it can result in a mucous cyst forming on the finger. As people tend to use their dominant hand more often, this could be why myxoid cysts occur more commonly on the patient’s dominant hand. Similarly, mucous cysts on the finger often occur when patients have osteoarthritis. This condition is also associated with the degeneration of the joints and is more common in older patients.

Alternatively, cells in the connective tissues, known as fibroblasts, may produce too much hyaluronic acid. When this happens, synovial fluid from the joint can increase and a cyst may form. If the patient has experienced trauma to the finger, this may prompt the production of hyaluronic acid and could result in a cyst developing.

Can a mucous cyst finger be treated?

When patients notice a lump or bump on their finger, they should seek advice from a doctor. Although a mucous cyst on the finger is not life-threatening, other possible causes should be ruled out. If a myxoid cyst is confirmed, the patient may be advised to leave it in situ, particularly if they are not experiencing any symptoms.

However, if the patient is experiencing pain or discomfort due to the mucous cyst, treatment may be offered. Depending on the severity of the cyst, various treatments are available, including:

  • Aspiration
  • Surgical removal
  • Cortisone injections
  • Cauterization

If the mucous cyst is aspirated, a physician will use a fine needle to remove fluid from the cyst. If necessary, a sample of this liquid can be sent for further analysis. Although the cyst should reduce in size once fluid is removed from it, the external wall of the cyst remains intact. As a result, the cyst could simply re-fill with fluid and reappear over time. In addition to this, fluid inside a mucous cyst can be fairly thick and may even have a jelly-like consistency. This can make it more difficult to remove via aspiration and some fluid may be left in the remaining cyst if it is too thick to be removed with a needle.

If aspiration is not a viable form of treatment for the patient, surgical removal may be more appropriate. There are various ways to carry out this type of cyst removal, but they all involve removing the mucous cyst intact. This means that the cyst will be removed as a whole, rather than just the fluid being removed.

Whilst preventing the existing cyst from simply refilling with fluid, it does not mean that the cyst won’t return. Mucous cysts on the finger are generally thought of as a chronic condition and they often recur, even if the whole cyst has been removed. Due to the likelihood of another cyst forming, many patients opt not to have a surgical removal, even though the procedure is usually minimally invasive.

In some instances, a cortisone injection may be an appropriate way to manage the patient’s symptoms. As a steroid, cortisone helps to reduce inflammation which, in turn, can minimize pain and swelling. Although this form of treatment doesn’t remove the mucous cyst from the finger, it can help to reduce the patient’s symptoms.

Cauterization may also be used to treat a mucous cyst on the finger, although this is not usually a first-line treatment for this type of condition. A physician will either perform an electrocautery, using heat to destroy the cyst, or chemical cautery, using specific chemicals to destroy the cyst tissue. Whilst cauterization can help to reduce a mucous cyst, the effects are often short-term as the rate of recurrence is particularly high for this type of cyst.

Although some treatments are effective in removing mucous cysts, the vast majority of patients develop another cyst following treatment. Due to this, many patients are keen to find treatments which effectively minimize their symptoms, even if this means leaving the mucous cyst intact.

If the cyst is particularly large, however, removal may be advisable. As the cyst grows larger, the risk of it rupturing increases. When this happens, the skin is open and could allow bacteria into the bloodstream. As the patient’s risk of infection would increase significantly, physicians may recommend that the mucous cyst is removed before it can rupture.

Can a mucous cyst finger be prevented?

As mucous cysts on the finger are often associated with degenerative conditions, such as osteoarthritis, it can be difficult to prevent them from forming. Whilst joint care throughout an individual’s life may reduce their chances of developing degenerative conditions, this is not always the case.

If a patient has treatment for mucous cyst finger, they may be keen to prevent the cyst from returning. Again, this can be a difficult task as mucous cysts are known to recur frequently. However, patients may be able to reduce the chances of a mucous cyst on the finger returning by performing hand exercises and maintaining movement as part of their treatment.