Digital Myxoid Cyst: Symptoms, Causes And Treatment

A digital myxoid cyst is a benign and small lump or swelling that usually develops at the base of fingernails or toenails. These non-cancerous lumps are also termed as digital mucous cyst or mucous pseudocyst. A myxoid cyst is usually not painful and in most cases, does not have any symptoms. Digital myxoid cysts are common and women are increasingly prone towards developing it when compared to that of men. Some myxoid cysts grow under the nail and can be very painful, but are rare ^[1] , ^[2] .

These benign growths are linked with osteoarthritis, with an estimated 64 per cent to 93 per cent of people with osteoarthritis have myxoid cysts. It mostly occurs between the ages of 40 and 70, although other cases have been reported too. These cysts are not signs of infections and do not spread from one individual to another ^[3] .

Symptoms Of Digital Myxoid Cysts

One must not get confused a mucous pseudocyst with that of lumps caused by itching or an insect bite. In order to understand that you have digital myxoid cysts, check for the following ^[4] , ^[5] :

• small round or oval bumps
• smooth, firm and filled with fluid
• not usually painful, but the nearby joint may have arthritis pain
• up to 1 centimetre (cm) in size (0.39 inch)
• skin coloured, or translucent with a reddish or bluish tinge and often looks like a pearl
• slow growing

Digital myxoid cysts usually develop on the middle or index finger, near the nail. It can split the nail, and cause nail loss.

If the lump near the fingers breaks and a sticky fluid leaks out, it could be a myxoid cyst ^[6] .

Causes Of Digital Myxoid Cysts

Although the precise and exact reason behind the benign cysts is not known, healthcare professionals have gathered some explanations that shine a light on its cause ^[7] .

• It can be caused as a result of fibroblast cells in the connective tissue producing excessive mucin, an ingredient of mucus. These type of cysts does not cause joint deterioration.
• The cyst can develop as a result of the degeneration of the synovial tissue around the finger or toe. And are associated with osteoarthritis and other degenerative joint diseases. It may also cause the development of a small bony growth from the degenerating joint cartilage.

In very rare cases, myxoid cysts can develop due to repetitive finger motion or trauma to the finger or toe (for people under 30) ^[8] .

Diagnosis Of Digital Myxoid Cysts

It is easy to understand the development of cysts. Your doctor will be able to analyse it by examining the lump but if the cyst arises under the nail, the diagnosis is more difficult. The doctor will advise for a scan or a biopsy for further examinations. The biopsy will include taking a sample from the cyst with a local anaesthetic ^[9] .

Treatment For Digital Myxoid Cysts

Unless and until the cyst becomes painful or hinders your daily life activities, no treatment is required. However, it is important that you keep an eye on the cyst as it normally does not shrink or get healed by itself ^[10] .

In many cases, the cysts have resurfaced even after treatments have been carried out. The treatment options for removing cysts are as follows ^[11] :

1. Non-surgical options

• Cryotherapy: Under this method, the cyst will be drained and liquid nitrogen will be used to alternately freeze and thaw the cyst. Cryotherapy help blocks any more fluid from reaching the cyst. The procedure may be painful and the recurrence rate is 14 per cent to 44 per cent.
• Infrared coagulation: Under this procedure, heat is used to burn off the cyst base. The recurrence rate is 14 per cent to 22 per cent.
• Carbon dioxide laser: Using the laser, the cyst base will be burned off, after it is drained. It has a 33 per cent recurrence rate.
• Intralesional photodynamic therapy: This treatment method involves draining the cyst, which will be followed by injecting a substance into the cyst to make it light-sensitive. Then, using laser light, the cyst base will be burned off. It is asserted to have a 100 per cent success rate.
• Repeated needling: Under this procedure, a sterile needle or knife blade will be used to puncture and drain the myxoid cyst. The process has to repeat for two to five times. The recurrence rate is 28 per cent to 50 per cent.
• Injection with a steroid or a sclerosing agent: Under this procedure, various chemicals such as iodine, alcohol, or polidocanol will be used; and has the highest recurrence rate of 30 per cent to 70 per cent.

2. Surgical options

With a high success rate of 88 per cent to 100 per cent, surgical treatments are the most recommended treatment option for myxoid cysts. The surgery will remove the cyst and cover the area with a skin flap that closes as it heals ^[12] .

3. Home remedies

If the cyst is not too severe, you can try treating it by firmly compressing the area for a few weeks.
Soaking, applying topical steroids and massaging can also help ^[13] .

Note: Do not try to drain or puncture the cyst at home as it increases the risk of infection.