Myxoid Cyst

What is a myxoid cyst?

A myxoid cyst is a small, shiny lump or growth most often found near a nail on your finger or toe. Other names for the condition are digital mucous cyst and digital myxoid cyst. You may hear your healthcare provider refer to it as a pseudocyst. This is because a true cyst has a capsule surrounding it, but a myxoid cyst doesn’t.

Digital mucous cysts are a type of ganglion cyst. A ganglion is a noncancerous (benign) soft tissue tumor that develops near a joint or tendon. Digital myxoid cysts are often ganglions that connect to the lining of your finger or toe joint. They show up between the joint and the nail.

Myxoid cysts are commonly associated with underlying health conditions such as osteoarthritis. They’re usually painless and don’t require treatment. However, you may want to seek treatment if they bother you or cause pain.

Who do myxoid cysts affect?

Myxoid cysts can affect anyone, but they’re most common in adults ages 40 and up. They affect people assigned female at birth three times as often as people assigned male at birth. Between 64% and 93% of people with osteoarthritis have myxoid cysts.

What are the symptoms of myxoid cysts?

Myxoid cysts are most common near the nail on the index, middle or ring finger of your preferred (dominant) hand. They’re not as common on your toes. You’ll usually only have one cyst, but you may develop more than one. They develop under your skin and attach to the joint by a stalk.

Myxoid cysts have a smooth, shiny surface. They’re usually skin-colored and look almost translucent (light can shine through). They range in size from 5 millimeters to 1 centimeter across, which is about the size of a pencil eraser. The round or oval bumps may be firm or filled with a jelly-like, sticky fluid. They typically don’t cause any pain. However, you may experience arthritis pain and stiffness in the nearby joint.

Rarely, a myxoid cyst may grow under your nail or involve the root of the nail. This type of cyst can be painful. It can cause a groove to develop down the length of your nail. You may also see slight depressions or color changes. Your nail may split or you may lose your nail.

What causes a myxoid cyst?

Researchers aren’t exactly sure what causes myxoid cysts. They appear to form when connective tissue weakens (degenerates). There are two variations:

• Osteoarthritis: Osteoarthritis and other degenerative diseases can cause the lining of your joints to grow excessively. This type of cyst looks like a ganglion cyst, which has a stalk that tracks back to the joint.
• Focal mucinosis: This condition occurs when abnormal deposits of mucins (mucopolysaccharides) build up in the skin under your finger or toe. Mucins are part of your mucus. This type of cyst isn’t associated with joint degeneration.

How is a myxoid cyst diagnosed?

Your healthcare provider may be able to diagnose a myxoid cyst with a physical exam. They’ll look at and feel the cyst. They’ll ask you questions about the cyst, including:

• How fast has it been growing?
• Does it cause you any pain?
• Have you noticed any color changes?
• Have you had any recent trauma to the area?

Your provider may request imaging tests or a biopsy to confirm a diagnosis, especially if the cyst is located under your nail. An X-ray can show evidence of osteoarthritis. A biopsy can rule out other medical conditions.

How do you get rid of a myxoid cyst?

Myxoid cysts may shrink or go away on their own. However, if they don’t, they’re usually not painful and don’t cause any other symptoms. Even when a cyst does disappear, it often comes back.

There aren’t many digital mucous cyst home treatment options. You can try firmly pressing on the cyst repeatedly for several weeks. Some studies say 39% of cysts may disappear using this method. But you shouldn’t try to drain or puncture the cyst yourself. This can cause an infection. Some people have tried applying a topical steroid to their cysts, but there’s no strong evidence that this method is effective.

When should I see my healthcare provider about a myxoid cyst?

You should have a myxoid cyst checked out by your provider if it’s causing you pain or affecting your quality of life. You should also see your provider if the cyst looks infected. Your provider will know how to treat a myxoid cyst on your finger or toe. They will suggest the best treatment option for you. If treatment is required, there are many options available.

How are myxoid cysts treated?

Surgical removal is the most effective treatment for a myxoid cyst, with a higher than 90% success rate. During surgery, your healthcare provider will cut the cyst away. They may also inject a dye into the joint to find and seal the point of fluid leakage. Your provider may scrape the involved joint and remove any bony outgrowths from the joint cartilage (osteophytes). Then, they’ll cover the area with a skin flap that closes as it heals.

There are many nonsurgical treatment options as well. Nonsurgical treatment options may include:

• Repeated sterile draining: Your provider will use a sterile needle or knife blade to puncture and drain the cyst. They may need to repeat the procedure two to five times.
• Steroid injection: Your provider will drain the cyst and then inject a steroid or other chemical (sclerosing agent) to shrink the fluid in the cyst.
• Cryotherapy: Your provider will first drain the cyst. Then, they’ll use liquid nitrogen to freeze and then thaw the cyst. Liquid nitrogen blocks more fluid from reaching the cyst.
• Carbon dioxide ablative laser: Your provider will drain the cyst and then use a laser to burn off (ablate) the cyst base.
• Infrared coagulation: Your provider will use infrared radiation which will convert into heat to burn off the cyst base.
• Intralesional photodynamic therapy: Your provider will drain the cyst and injects a substance into it that makes it light-sensitive. Then, they’ll use a laser light to burn off the cyst base.

What can I expect if I have a myxoid cyst?

Most myxoid cysts don’t cause any pain or other symptoms. They may go away on their own but they may not. If a cyst bothers you, talk to your healthcare provider about treatment options. It’s important to note that some treatment options can leave scars, cause pain or swelling, or decrease your joint range of motion.

In addition, myxoid cysts have a tendency to return after treatment. Surgical removal tends to have the lowest recurrence rate at only 2% as long as your surgeon removes the stalk along with the cyst. Intralesional photodynamic therapy also has a very high success rate. In one small study, 100% of people who used this method saw no cyst recurrence after 18 months.

Other recurrence rates range from 14% to 70% depending on the method of treatment.

A note from Cleveland Clinic

Myxoid cysts are small, noncancerous bumps that are usually associated with osteoarthritis. They’re typically painless and may go away on their own. You should speak to your healthcare provider about treatment if they bother you, cause pain or look infected. Your provider can discuss various surgical and nonsurgical treatment options. But it’s important to remember that treatment options often come with side effects such as pain and scarring. In addition, myxoid cysts tend to recur after treatment.