Myxoid Cysts - Causes, Symptoms, Diagnosis, and Treatment

Introduction:

A cyst is a small, sac-like structure filled with fluid, gas, or cheesy white material. It can occur in any part of the body. The myxoid cyst is a shiny, small, noncancerous bump located at the joint close to the end of the finger. These cysts are mostly associated with underlying medical conditions such as osteoarthritis (a form of arthritis brought on by the breakdown of the flexible tissue at the ends of bones). Arthritis is the inflammation of the joints, causing stiffness and pain. These cysts do not require any treatment. However, surgical removal is the most effective treatment if required or considered.

What Is a Myxoid Cyst?

• It is a subtype of ganglion cyst typically situated in the distal interphalangeal joint of the finger, which is the joint closest to the tip of the finger.

• A ganglion is a noncancerous tissue growth found near a joint or a tendon.

• It is located on the lateral border of the joint, back of the hand, and not in the midline.

• Sometimes, myxoid cysts can penetrate the nail bed.

• Cysts are connected to the joint by a structure called a stalk.

• These cysts are filled with thick gelatinous material, primarily hyaluronic acid.

• It is a pseudocyst because a capsule does not surround it, but a capsule surrounds the true cyst.

What Are the Other Names for Myxoid Cysts?

Myxoid cysts have many other names. They are as follows:

• Digital mucous cysts.

• Digital ganglion cysts.

• Digital synovial cysts.

What Are the Causes of Myxoid Cysts?

The exact cause for the development of myxoid cysts is not known. Studies suggest cysts develop when there are degenerative changes in the connective tissue at the final segment of the finger. Two variations are found. They are as follows.

1. Osteoarthritis - Degenerative disorders like osteoarthritis make the lining of the joints grow abnormally. This type of cyst contains a stalk that extends back to the joint, similar to ganglion cysts.

2. Focal Mucinosis - This disorder develops when abnormal mucin (mucopolysaccharide) deposits accumulate in the skin under the finger or toe. A component of mucus is mucin. Joint deterioration is not linked to this kind of cyst.

What Are the Symptoms of Myxoid Cysts?

• Myxoid cysts are smooth, skin-colored, and almost translucent.

• Their size ranges from 0.19 to 1.96 inches.

• The bumps may be firm or filled with sticky fluid.

• Myxoid cysts are most frequently found close to the dominant hand's nail on the index, middle, or ring finger. They are less frequent on toes.

• Usually, only one cyst is present, but in rare cases, more than one cyst may be present.

• They grow beneath the skin and attach to the joint by the stalk.

• Cysts may develop suddenly or gradually over time.

• Smaller cysts may not exhibit any symptoms, while larger cysts may be painful or uncomfortable during regular activities.

• The fingernail may develop an abnormal shape, such as a notch or ridge, if the cyst is adjacent to the fingernail bed.

• The overlying skin on the finger may become irritated. If the skin breaks, the cyst may release the viscous, thick fluid that fills the cyst.

Who Is Affected by Myxoid Cyst?

Myxoid cysts can develop at any age, but they are most common in adults aged 40 and above.

Women are more frequently affected than men. About 64 to 93 percent of osteoarthritis patients have myxoid cysts.

What Are the Complications of Myxoid Cyst?

Some complications are as follows:

• Postoperative pain from underlying distal interphalangeal joint arthritis.

• Soft tissue defect.

• Soft tissue infection.

• Joint stiffness.

• Nailbed injury or deformity.

• Osteomyelitis - Inflammation of bone caused by infection.

How Is It Diagnosed?

Myxoid cysts are usually diagnosed by physical examination. The physician might ask some questions related to the cyst, which may include:

• How rapidly has it been expanding?

• Is there any discomfort or pain?

• Are there any color variations?

• Was there any recent injury on the site of the cyst?

Imaging tests or biopsy is required to confirm the diagnosis if the cyst is under the nail. An X-ray can reveal osteoarthritis symptoms. A biopsy can rule out other medical diseases. The biopsy removes a small piece of tissue under local anesthesia and examines it under the microscope for any changes.

What Are Differential Diagnoses?

Some differential diagnoses are as follows:

• Gout - A type of arthritis characterized by joint pain and redness.

• Heberden's Node - A small, pea-sized bony growth on the joint closest to the fingertip.

• Giant Cell Tumor - A noncancerous growth that develops near a joint at the end of the bone.

What Are the Treatment Options for Myxoid Cyst?

Myxoid cysts are treated in a variety of ways, and the advantages and disadvantages of each have been closely investigated. The following are some of the treatment methods.

1. Non-surgical Methods: Some of the non-surgical treatment methods are as follows:

• Infrared Coagulation: In this procedure, infrared light is used as a heat source to burn the cyst base of the cyst.

• Cryotherapy: After the cyst has been drained, it is frozen and thawed repeatedly using liquid nitrogen. Liquid nitrogen blocks fluid from entering the cyst. This procedure has a 14 to 44 percent chance of recurrence. Sometimes, cryotherapy can be painful.

• Carbon Dioxide Laser: The laser is used to burn the cyst base after draining the cysts. This procedure has a 33 percent recurrence rate.

• Intralesional Photodynamic Therapy: The cyst is drained and injected with a light-sensitive material during this procedure. The cyst base is then removed using laser light. A study shows a 100 percent success rate with this method with no recurrence rate after 18 months.

• Repeated Needling: The myxoid cyst is punctured and drained using a sterile needle or knife blade during this treatment. The probability of a cyst recurrence ranges from 28 to 50 percent.

• Steroid Injections: The cyst is drained and injected with steroids or other chemicals to reduce the fluid in the cyst.

2. Steroid Injections

Surgical removal of myxoid cysts is the most effective treatment method. It has a success rate of about 90 percent. It involves cutting the cyst away and covering it with a skin flap that covers it as it heals. Sometimes, a dye is injected into the joint to identify and close the leakage point. Scraping the involved joint and removing the bony outgrowths from the joint cartilage is performed. The skin flap's size depends on the size of the cyst.

What to Expect if There Is a Myxoid Cyst?

The majority of myxoid cysts do not display any symptoms or cause any pain. They might resolve on their own, but they might also not mend. Consult the doctor regarding the treatment choices if the cyst poses hurdles to day-to-day activities. It is important to remember that some treatment methods may result in scarring, discomfort, swelling, and a reduction in the range of motion in the joints. Additionally, myxoid cysts frequently recur following treatment. When the stalk is removed during surgical removal, the recurrence probability is often only 2 percent.

Conclusion:

Myxoid cysts are small, noncancerous growth typically located in the joint closest to the fingertip. Though painless, it may sometimes get infected or hinder daily activities. In such situations, medical intervention can be considered. It is always advisable to consult a physician to diagnose and determine the exact treatment method.