Digital Myxoid Cyst

A digital myxoid cyst (sometimes called a mucous cyst) is a non-cancerous swelling that occurs on the fingers or, sometimes, on the toes. The cyst is often connected to the finger lining or toenail joint and is usually located between the joint and the nail. Digital myxoid cysts are not contagious and are not a form of skin cancer. The term cyst is from the Greek word kystis, meaning a bag or pouch; myxoid and mucoid refer to the jelly-like contents. Digital derives from the Latin word digitus, meaning finger or toe. A small number of people might develop these because of excessive repetitive finger motion.

The exact cause is not known. Digital myxoid cysts occur most frequently in people in their sixties, but these may develop at any age. Individuals with osteoarthritis and women and are more at risk of developing these. In some cases, mainly if it grows under the age of 30, a history of trauma involving a finger or toe might be there.

Digital myxoid cysts are skin-colored, red or slightly translucent (letting light shine through) and usually up to 1 cm in size. These are more likely to develop on the index or ring fingers of the dominant (preferred) hand. If a cyst is overlying the area where the nail is formed, it may cause a groove to occur along the length of the nail, which can vary in width. Occasionally, slightly sticky, clear, straw-colored, or blood-stained contents may leak out of the cyst. Usually, there is just one cyst, but some people may develop more than one, on the same or different fingers.

Digital myxoid cysts are slow-growing over months and usually not painful but may become tender, especially when knocked. There may also be symptoms of arthritis with pain, stiffness, and deformity of the joint adjacent to the cyst. Digital myxoid cysts may become inflamed. If a myxoid cyst suddenly becomes more massive, painful, red, and hot, you should see your doctor as these symptoms may indicate infection, and an antibiotic may be prescribed.

A digital myxoid cyst is usually easily recognized by medical professionals as a small lump overlying the end joint of the finger or toe with or without a groove in the adjacent fingernail. The occasional discharge of transparent, slightly sticky material from the cyst is also characteristic. If the cyst arises under the nail, the diagnosis is more complicated, and then a scan or a sample (biopsy) from the cyst taken by your doctor with a local anesthetic may be needed.

Several different treatment options exist for digital myxoid cysts; however, myxoid cysts may recur after treatment. They may disappear spontaneously.

If a digital myxoid cyst does not cause any symptoms, no treatment is required. Rarely, these can shrink and resolve on their own. If treatment is needed, there are several options available; however, the digital myxoid cyst might reoccur. Some of the treatments may cause pain and swelling of the site treated, leave scars, and reduce the range of motion in the finger or toe joint. 

Common treatments are usually not requiring a local anesthetic: • Repeated drainage of the cyst fluid using a sterile needle or blade. • Freezing of the cyst with liquid nitrogen (cryotherapy). • Injection with steroids or a chemical that shrinks the cyst.

Treatments requiring a local anesthetic: Surgical therapies have a higher success rate. These include • Scraping the cyst off (curettage). • Finding the point of leakage of fluid from the joint by injection of dye into the joint, and then closing that leak (this may be performed by orthopedic, plastic, or hand surgeons). • Removing the cyst by cutting it away. • Cauterising the cyst (burning it off)