A mucoid cyst is a type of ganglion cyst which affects the end joint of the finger. It may appear as a small lump near the fingernail and can sometimes cause nail grooving, nail deformity or discharge of clear jelly-like fluid.
Mr Robert Farnell is an experienced specialist Consultant Orthopaedic Hand and Wrist Surgeon who has been working in Leeds for over 25 years. He exclusively treats conditions affecting the adult hand and wrist, including carpal tunnel syndrome, trigger finger and thumb, thumb arthritis and Dupuytren’s disease.
What is a mucoid cyst?
A mucoid cyst is a ganglion affecting the end finger joint. This joint is called the distal interphalangeal joint, or DIP joint.
Mucoid cysts are benign and are not cancerous. They are often associated with underlying osteoarthritis in the end joint of the finger.
Symptoms of a mucoid cyst
A mucoid cyst usually appears as a small lump close to the fingernail. It may be painless, although some patients experience discomfort, tenderness or pain from the underlying finger joint arthritis.
Symptoms may include:
- A small lump near the end finger joint
- Grooving or deformity of the fingernail
- Pain or stiffness in the end finger joint
- Clear jelly-like discharge if the cyst opens
- Occasional infection if the cyst leaks or breaks down
What causes a mucoid cyst?
Mucoid cysts usually develop as a consequence of osteoarthritis affecting the end joint of the finger. The cyst contains thick jelly-like fluid, similar to other ganglion cysts.
The cyst may fluctuate in size and can sometimes affect the nail as it grows from the nail fold.
How is a mucoid cyst diagnosed?
Diagnosis is usually made from the appearance of the lump and clinical examination. An X-ray may be useful because mucoid cysts are often associated with osteoarthritis of the end finger joint.
Find out what to expect at your outpatient appointment.
Treatment for a mucoid cyst
Treatment depends on the size of the cyst, whether it is painful, whether it has discharged fluid, whether there is nail deformity and whether there is underlying arthritis in the joint.
Observation
If the cyst is small, painless and not causing problems, it may be reasonable to monitor it without treatment.
Surgical treatment
Surgery may be considered if the cyst is painful, repeatedly discharging, causing nail deformity or becoming infected.
Surgery usually involves removing the cyst and addressing its connection with the underlying joint. Any associated bony prominence from osteoarthritis may also be treated at the same time.
Read more about ganglion excision.
Possible complications
Complications are uncommon but may include wound infection, temporary scar tenderness, stiffness, recurrence of the cyst or ongoing symptoms from arthritis in the end finger joint.
Read more about post-operative care.
Concerned about a lump near your fingernail?
If you have a lump near the end of your finger, nail changes or discharge from a cyst, Mr Robert Farnell can assess your finger and advise whether monitoring or treatment may be appropriate.
Mucoid cyst FAQs
What is a mucoid cyst?
A mucoid cyst is a type of ganglion cyst which affects the end joint of the finger, close to the fingernail.
Is a mucoid cyst cancerous?
No. A mucoid cyst is benign and is not cancerous.
What causes a mucoid cyst?
Mucoid cysts are often associated with osteoarthritis affecting the end finger joint.
Can a mucoid cyst affect the nail?
Yes. A mucoid cyst can cause grooving, ridging or deformity of the fingernail.
Can a mucoid cyst leak fluid?
Yes. A mucoid cyst may discharge clear jelly-like fluid. If this happens, infection can occasionally develop.
When should a mucoid cyst be treated?
Treatment may be considered if the cyst is painful, repeatedly discharging, infected, causing nail deformity or affecting hand function.
Can a mucoid cyst come back after treatment?
Yes. Recurrence can occur, particularly because mucoid cysts are often associated with underlying arthritis in the end finger joint.