What is Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)?
Digital mucous cysts are a kind of lump often found on the hand. These lumps, called ganglions, are soft tissue growths located near a joint or a tendon. Specifically, a digital mucous cyst is a ganglion that comes from the back part of the joint closest to the fingertip, known as the distal interphalangeal joint, or DIP joint for short. It’s common for these cysts to be linked with arthritis in the DIP joint.
What Causes Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)?
The exact cause of digital mucous cysts is not currently known. However, these cysts are usually linked with a condition called osteoarthritis, which affects the DIP joint of the finger.
Risk Factors and Frequency for Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
Digital mucous cysts are a common kind of lump found on the hand. They account for about 60% of lumps discovered in the wrist and hand. More women than men tend to have them, with women being three times more likely to be affected. Usually, these cysts are seen in middle-aged to elderly people.
Signs and Symptoms of Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
When diagnosing soft tissue conditions, it’s really important to take a thorough history from the patient. Key questions should cover any underlying health issues that might be affecting the condition, as well as any relevant family medical history. Details about the growth speed of the lump, whether it’s causing any pain or changing color, and any recent injuries to the area are also crucial.
Digital mucous cysts of the hand usually show up as a lump on the back side of the end joint of a finger. These lumps grow slowly, are located just under the skin, and are not very mobile. If you shine a light on them, they may be slightly see-through, and they feel firm to the touch. Mucous cysts usually are round and dome-shaped and can be different sizes. The lump usually doesn’t sit directly on top of the joint; it’s often to one side because it’s pushed over by the tendon but remains connected to the joint by a slender connection known as a stalk.
These lumps can sometimes cause finger nail deformities if they put pressure on the fingernail root. This pressure can lead to ridges forming along the length of the nail. The skin over the lump should be examined to see how thick it is and to ascertain the potential need for a skin graft if surgery is needed. The skin may also often be broken and the cyst could be open, draining and possibly infected.
Testing for Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
After your doctor performs a physical examination, they may take x-rays of your hand. These x-rays can potentially reveal signs of osteroarthritis in your distal interphalangeal (DIP) joint, which is a joint located in your fingers. Such signs could include hardened bone beneath the cartilage of the joint, bone spurs, and a reduced space within the joint.
Treatment Options for Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
For small cysts, the initial approach can be keeping an eye on them without any active treatment. If they cause discomfort or grow larger, then they can be physically drained or removed. However, using corticosteroid injections, which can thin the skin, are not advised. If the skin over the cyst becomes thin or if there’s deformity causing pain, more aggressive intervention could be considered. It’s important to understand that if the cyst was linked to arthritis in the joint, removal of the cyst alone may not alleviate all the pain.
Aspiration or draining the cyst might be a possible solution for those aiming to avoid surgery, but the downside is that the cyst can come back about half of the time. Surgery is usually chosen to lower the chance of cyst reappearance or when non-surgical options have failed. The surgery involves removing the part of the cyst growing out of the joint, the surrounding joint capsule, and any bony outgrowths. Skin protection is crucial during surgery to prevent any post-surgery complications.
The surgery involves a careful procedure to prevent any damage to the nailbed, which is often very close to the cyst. A special incision is made on the finger’s joint or centered on the cyst itself. After identifying the cyst, it’s carefully separated from the tissue down to its base which can then be sealed off, and any bony outgrowths are removed.
Getting rid of the bony outgrowth can also lower the chance of the cyst coming back to less than 10%. If there’s a concern over the skin thickness after the removal, the surgeon might consider a skin graft, a minor movement of nearby skin, or rotation of skin. If the skin defect is bigger than 2cm, there’s an option of using the skin supplied by small arteries in the area, but this is a more complex procedure.
One way to ensure the cyst does not return is to fuse the joint, but there are several techniques to consider. These include using wires, or screws, both with or without a “head”. Each technique has its risks, such as infection, skin damage or incorrect sizing that might press on the nail bed leading to nail deformities like a split nail. For wires used inside the bone, the failure rate can be as high as 12%, while other methods tend to have very high successful fusion rates, from 92% to 100%.
What else can Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon) be?
Gout, giant cell tumor, and Heberden’s node are medical terms which represent different health conditions:
- Gout involves sudden, severe attacks of pain, redness and tenderness in joints, often the joint at the base of the big toe.
- A Giant cell tumor is a rare, non-cancerous tumor that often develops near a joint at the end of the bone.
- Heberden’s node is characterized by bony swellings that can develop in the distal finger joints, usually seen in cases of severe osteoarthritis.
What to expect with Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
After a surgical procedure to remove a cyst, there is a 2% chance that the cyst might come back, but this only happens if the stalk of the cyst is also removed during surgery. If the cyst is taken out but the stalk is left behind, the chance of the cyst reappearing can be as high as 25 to 50%.
It’s been observed that after injecting corticosteroids into the cyst, the possibility of the cyst returning can be extremely high, ranging from 68 to 100%. If the cyst is drained through aspiration (a process where fluid is drawn out from the cyst), there’s a 50% probability that it will reoccur.
For patients who are dealing with pain due to worn-out joint disease affecting the DIP joint of their finger, a surgical procedure known as arthrodesis can be performed. However, it’s important to note that if a patient chooses to have surgery without treating the arthritis in the DIP joint, they should be aware that they might still have pain after the operation.
Possible Complications When Diagnosed with Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
- Return of the condition
- Post-surgery pain due to arthritis in the DIP joint, which is one of the joints in the fingers
- Damage to the soft tissue
- Infection in the soft tissue
- Having a draining sinus tract – a channel that can drain pus from an infection
- Stiffness in the joint
- Injury or deformity in the nail bed
- Damage to the extensor tendon, i.e., the tendon that enables you to open your hand
- Osteomyelitis, a bone infection
Recovery from Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
After surgery, a tight bandage is used to protect the wound. This bandage is typically removed two weeks after the operation. If the skin isn’t healing well or if there’s potential damage to the tendon in the extended part of the finger, a finger brace may be used. This brace, which includes the furthest joint in the finger (known as the DIP joint), can be placed on either the palm side or the backside of this joint for about 10 days. Braces attached on the palm side can help reduce any pressure on the surgical cut.
Usually, the joint closest to the hand (the PIP joint) is left uncovered, and it’s suggested to gently stretch and move this joint to avoid it becoming stiff.
Preventing Digital Mucous Cyst (Benign Soft Tissue Tumor Found Next to a Joint or Tendon)
It’s crucial to highlight the possibility of the problem returning with different treatments. Importantly, patients should also know that the source of their pain may not actually be the cyst, but rather a type of arthritis in the joint called DIP joint osteoarthritis.
As a healthcare provider, discussing with your patient and ensuring they grasp the potential risks of surgery as well as the diverse treatments available is vital. This information helps the patient to make an informed decision about their care.
