Overview

A myxoid cyst is a small, round, or oval-shaped lump that often appears on the fingers or toes. These cysts are typically filled with a jelly-like substance and can vary in size, from a few millimetres to a centimetre or more. While myxoid cysts are generally not painful, they can be bothersome due to their appearance or location, which might lead to discomfort when wearing shoes or engaging in activities that involve motor skills.^1,7

Myxoid cysts are also known by other names, including digital mucous cysts or mucous pseudocysts. The term "myxoid" refers to the jelly-like consistency of the fluid within the cyst. These cysts are not cancerous and do not pose a significant health risk, but they may require treatment if they become painful or affect the function of the affected finger or toe.²

Myxoid cysts typically develop on the distal phalanx, which is a bone at the tip of the finger or toe. They are often found near the nail bed, and they can cause changes in the nail's appearance. The cyst itself is usually connected to the joint capsule, and it is filled with a clear, gelatinous fluid. The presence of a myxoid cyst can cause pressure on the nail matrix, leading to a groove or indentation in the nail.^4,6

Causes of Myxoid Cysts

The exact cause of myxoid cysts is still unknown. While their precise origin remains uncertain, several factors and theories have been proposed to explain the development of these cysts:

• Joint Degeneration: Myxoid cysts are often associated with joint degeneration, particularly in the fingers. This suggests that the cysts may be linked to osteoarthritis, a condition where the cartilage and joint tissues deteriorate over time.
• Minor Trauma: Some experts believe that minor trauma or repeated microtrauma to the affected finger or toe may contribute to the development of myxoid cysts. This could include activities such as frequent typing, pinching, or squeezing of the fingers.
• Age: Myxoid cysts tend to be more common in older individuals, which aligns with the idea that joint degeneration and age-related changes in the fingers play a role in their formation.
• Genetics: There may be a genetic predisposition to myxoid cysts, as they sometimes occur in families. This suggests that there may be a hereditary component to their development.
• Synovial Fluid Leakage: The fluid within myxoid cysts resembles synovial fluid, the lubricating fluid found in joints. Some theories suggest that myxoid cysts may form when synovial fluid is leaked from the joint into the surrounding tissues forming a cyst.While these factors may contribute to the development of myxoid cysts, the exact mechanism by which they form is not fully understood. Further research is needed to uncover these cysts' precise causes and the associated with it physiological changes.^2,3,7

Symptoms

Myxoid cysts typically present with the following symptoms:

• Visible Lump: The most noticeable symptom of a myxoid cyst is a small, round, or oval-shaped lump. The cyst is usually firm to the touch and may vary in size.
• Nail Changes: Myxoid cysts that develop near the nail bed can cause changes in the appearance of the nail. This can include grooves, ridges, or deformities in the affected nail.
• Discomfort: While myxoid cysts are not usually painful, they can become uncomfortable, especially if they are pressed against or irritated by footwear or when using the affected finger or toe.
• Nail Rupture: In some instances, myxoid cysts may rupture, causing the clear, jelly-like fluid inside to leak. This can lead to temporary relief from the cyst's pressure and discomfort.^1,4

Diagnosis

The diagnosis of a myxoid cyst can be made through a physical examination by a healthcare provider. Your doctor will inspect the affected finger or toe and may ask about your medical history and any recent injuries or trauma to the area.

In some cases, your medical practitioner may choose to use imaging techniques, such as ultrasound or MRI (magnetic resonance imaging), to get a better look at the cyst and the surrounding structures. These imaging studies can help confirm the diagnosis and rule out other potential causes of the lump.

If there is any uncertainty about the nature of the cyst, a sample of the fluid inside the cyst may be collected and sent for laboratory analysis. This is typically done when there is a concern about the cyst being something other than a myxoid cyst, such as an infection or a tumour.⁶

Treatment Options

The treatment of myxoid cysts is not always necessary, especially if they are not causing discomfort or functional impairment. Many myxoid cysts can resolve on their own, and in some cases, they may rupture spontaneously, relieving any discomfort associated with the cyst.⁵

Surgical Procedures

In cases where myxoid cysts are causing significant discomfort or functional impairment, or if they are cosmetically bothersome, surgical procedures may be considered. There are several surgical techniques that healthcare providers can employ to address myxoid cysts, including:

• Needle Aspiration: In this minimally invasive procedure, a healthcare provider uses a syringe and a fine needle to withdraw the fluid from the cyst. This can provide immediate relief from discomfort and reduce the size of the cyst. However, there is a risk of the cyst returning after aspiration.
• Cyst Excision: Cyst excision is a more definitive treatment option. In this procedure, the cyst is surgically removed, including the cyst wall, to prevent its recurrence. This is typically done in a sterile environment, and the patient may receive local anaesthesia. The procedure usually results in a small incision, and stitches or sutures may be needed to close the wound. Cyst excision is often performed in an outpatient setting, and the recovery period is relatively short.
• Marsupialization: Marsupialization is a surgical technique that involves creating a small opening in the cyst and suturing its edges to the surrounding skin. This allows for the continuous drainage of fluid and reduces the likelihood of cyst recurrence. It is a suitable option for larger or recurrent myxoid cysts.^4,5,6

Prognosis

The prognosis for myxoid cysts is generally positive. These cysts are benign and do not pose a significant health risk. The majority of myxoid cysts can be effectively managed with conservative treatments or, if necessary, surgical procedures. Aspiration and excision typically provide a high rate of success in terms of symptom relief and preventing cyst recurrence.

However, it's worth noting that myxoid cysts can occasionally return, even after successful treatment. Recurrence is more common if only the cyst contents are aspirated, without removal of the cyst wall. Marsupialization or complete cyst excision reduces the likelihood of recurrence.⁷

Prevention

Preventing the development of myxoid cysts can be challenging since their exact cause is not fully understood. However, there are some strategies that individuals can consider to potentially reduce their risk of developing these cysts like maintaining good nail hygiene and avoiding practices that may damage the nail bed can be beneficial. Maintaining overall joint health and well-being through a balanced diet, regular exercise, and looking after your joints can potentially reduce the risk of joint degeneration, which may be associated with the development of myxoid cysts.

It's essential to keep in mind that while these prevention strategies may help reduce the risk, myxoid cysts can still develop in individuals who take good care of their hands and fingers. Regular self-examination and early intervention, if a cyst does appear, are essential to managing this condition effectively.^5,6

Summary

Myxoid cysts, also known as digital mucous cysts or mucous pseudocysts, are benign (non-cancerous) lumps that often develop on the fingers or toes. Although these cysts are generally not painful or life-threatening, they can cause discomfort and cosmetic concerns. The exact cause of myxoid cysts remains somewhat elusive, but they are commonly associated with joint degeneration, minor trauma, and possibly genetic factors.

Diagnosing myxoid cysts is typically straightforward, involving a physical examination and, in some cases, imaging studies or fluid analysis. While many myxoid cysts may resolve on their own or rupture spontaneously, treatment options are available for those who experience discomfort, functional impairment, or cosmetic issues.

Treatment options range from home remedies like warm soaks and topical steroids to surgical procedures such as needle aspiration, cyst excision, and marsupialization. The prognosis is generally favourable, with a high success rate for symptom relief and prevention of recurrence.

Prevention of myxoid cysts is not always possible due to their unclear aetiology, but individuals can take steps to reduce their risk by protecting their fingers and promoting joint health. If you suspect you have a myxoid cyst or are experiencing discomfort or cosmetic concerns related to one, it is essential to consult with a healthcare provider for evaluation and treatment.