What are the aims of this leaflet?

This leaflet has been written to help you understand more about digital myxoid cysts - what they are, what causes them, what can be done about them and where you can find out more information about them. 

What is a digital myxoid cyst?

A digital myxoid cyst (sometimes called a mucous cyst) is a non-cancerous swelling that occurs on the fingers or, sometimes, the toes. The cyst is often connected to the lining of the finger 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 kystis meaning a bag or pouch; myxoid and mucoid refer to the jelly-like contents. Digital derives from the Latin digitus, meaning finger or toe. A small number of people might develop these because of excessive repetitive finger motion. 

What causes a digital myxoid cyst?

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 to develop these. In some cases, especially when these develop in people under the age of 30, there might be history of trauma in the past to the finger or toe involved.

Is a digital myxoid cyst hereditary?

Digital myxoid cysts are not passed from one generation to the other.

What does a digital myxoid cyst look like?

Digital myxoid cysts are skin-coloured, 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-coloured 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.

What are the symptoms of a digital myxoid cyst?

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 larger, painful, red and hot, you should see your doctor as these symptoms may indicate infection and an antibiotic may be prescribed. 

How is a digital myxoid cyst diagnosed?

A digital myxoid cyst is usually easily recognised 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 clear, slightly sticky material from the cyst is also characteristic. If the cyst arises under the nail, the diagnosis is more difficult, and then a scan or a sample (biopsy) from the cyst taken by your doctor with a local anaesthetic may be needed. 

Can a digital myxoid cyst be cured?

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

How can a digital myxoid cyst be treated?

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 required, there are a number of options available, however it is possible that 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 usually not requiring a local anaesthetic:

• Repeated drainage of the cyst fluid using a sterile needle or blade.
• Freezing of the cyst with liquid nitrogen (cryotherapy).
• Injection with steroid or a chemical that shrinks the cyst.

Treatments requiring a local anaesthetic:

Surgical treatments 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 orthopaedic, plastic or hand surgeons).
• Removing the cyst by cutting it away.
• Cauterising the cyst (burning it off).

Where can I get more information about digital myxoid cysts?

http://www.emedicine.com/derm/topic100.htm (includes photographs)

http://dermnetnz.org/lesions/mucous-cyst.html (includes photographs)

https://www.healthline.com/health/myxoid-cyst (includes photographs)

Jargon Buster: https://www.skinhealthinfo.org.uk/support-resources/jargon-buster/

Please note that the BAD provides web links to additional resources to help people access a range of information about their treatment or skin condition. The views expressed in these external resources may not be shared by the BAD or its members. The BAD has no control of and does not endorse the content of external links.

This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.

This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel

BRITISH ASSOCIATION OF DERMATOLOGISTS PATIENT INFORMATION LEAFLET

PRODUCED JULY 2009

UPDATED JULY 2012, FEBRUARY 2016, JULY 2019

NEXT REVIEW DATE JULY 2022