Myxoid cysts, also known as digital mucous cysts, are small, fluid filled lumps that can appear on the fingers or the toes. They are not harmful, but they can sometimes indicate an underlying condition, such as osteoarthritis.
Keep reading to learn more about the causes and symptoms of myxoid cysts, as well as the treatment options available.
A myxoid cyst is a small lump, filled with fluid, that usually appears close to a joint on the finger. In some cases, they can also appear on the toes, but this is less common.
Myxoid cysts tend to be more common in middle-aged and older adults, but they can occur at any age.
Although myxoid cysts are not usually painful, they can be tender if they put pressure on other structures, such as nerves.
Most complaints about myxoid cysts are that they look unattractive, get in the way of routine activities, or both.
Myxoid cysts grow slowly, usually over a period of months. The cysts appear as small, smooth bumps, or nodules, on the fingers and can range in size from 5 millimeters (0.2 inches) to 1 centimeter (0.4 inches).
In some cases, multiple cysts may appear on the same finger. Cysts may also appear on multiple fingers.
Myxoid cysts tend to appear near the joints of the index or middle finger. Cysts that appear near the base of a fingernail or toenail may sometimes cause nail deformity. In certain cases, cysts can also grow under the nail, creating a depression in the middle of the nail or causing the nail to split.
The nodules can be skin colored, translucent, or reddish-blue. Each nodule is filled with a thick fluid called synovial fluid. This is the fluid that surrounds joints and tendons, protecting them from damage during movement. Sometimes, this sticky fluid leaks out of the cyst. It may be clear, yellowish, or pinkish.
Myxoid cysts are not usually painful. However, if the cyst develops due to an underlying condition, such as osteoarthritis, a person may feel pain in the nearby joint. The cyst may also feel tender if a person knocks it.
Occasionally, a cyst may also reduce joint movement.
It is not always clear what causes myxoid cysts, but medical experts tend to agree that there are three main contributing factors:
- Having osteoarthritis or another degenerative joint condition: This is because joint inflammation can cause synovial fluid to leak from the joint, causing a cyst to form.
- Having an overproduction of a substance called mucin in the connective tissue cells, or fibroblasts: This is not connected to any degenerative joint condition and is not usually caused by any other underlying condition.
- Having injured a finger or toe in the past: This could especially be the case in younger people.
Myxoid cysts are more common in middle-aged and older adults, as well as in women. This is because people in these groups are more likely to have osteoarthritis.
The following factors may also
- Obesity: Carrying more weight puts more strain on the joints.
- Using the joints repetitively: This can damage joints and increase the risk of osteoarthritis.
- Genetics: Having a family history of osteoarthritis means that a person is more likely to develop it themselves.
People may wish to seek medical advice for a myxoid cyst if it:
- causes them to be unhappy
- causes pain or discomfort
- interferes with routine tasks
- becomes infected
A healthcare provider will examine the appearance and location of a cyst and ask about any other symptoms the person has notcied.
They will then discuss the range of treatment options available and the benefits and risks of each.
They may also recommend a biopsy to rule out any other undiagnosed health conditions.
A number of treatment options are available, including both surgical and nonsurgical options.
The sections below will cover these in more detail.
A healthcare provider may recommend trying a nonsurgical method of removal first. This may include:
- using infrared heat, laser, or light therapy to burn off the cyst base
- using liquid nitrogen, or cryotherapy, to freeze and then thaw the cyst, which can reduce its size but does not prevent the fluid from building up again
- draining the cyst by making a puncture, though this may need to take place several times
- injecting the cyst with steroids or chemicals to shrink the volume of fluid
It is worth noting that all the methods above have a recurrence rate. This means that the cyst could grow back again after treatment.
Never try to remove or drain a cyst at home. A trained physician needs to carry out the procedure in a sterile environment. This helps prevent infection or other further complications.
Surgical treatments for permanent removal have a much higher rate of success, at around 95%. This means that a doctor may recommend surgery as a first option. Surgery is likely to occur under local anesthetic, and the procedure usually lasts around 30 minutes.
During the procedure, a surgeon will cut the cyst away, along with any connecting tissue with the joint, and cover the wound with a flap of skin. This may be skin from a skin graft or the skin from above the cyst. The surgeon may also scrape away any small bony growths, or bone spurs, from the joint.
They can then sew the flap shut or leave it to grow over the wound. The scarring that develops may prevent more fluid from leaking into the cyst again.
After the surgery, a person will need to wear a splint and do daily exercises, usually for at least 2 weeks. They may experience some tenderness or soreness in the area while it is healing.
Any nail deformity will usually disappear gradually by itself after surgery.
However, there is no evidence to suggest that other home remedies, such as soaking or massaging the fingers and toes, are effective as permanent treatments for myxoid cysts.
Myxoid cysts are small, benign lumps that form on the fingers or toes. They are not cancerous and are not usually painful.
They are more common in middle-aged and older adults, as well as in people with an underlying degenerative joint condition, such as osteoarthritis.
Risk factors include age, sex, weight, previous injury, and repetitive movement.
There is no proven way of preventing myxoid cysts from occurring.
Treatment for myxoid cysts includes a range of nonsurgical and surgical options, though there is some anecdotal evidence to suggest that certain home remedies may also help.