What are they?
Ganglions are fluid-filled sacs that usually communicate either with an underlying joint or tendon sheath. They are benign and pose no threat to the patient's general health. The fluid contents are thick, gelatinous and under some tension, giving the resultant lump a firm feel. The commonest site for a ganglion is the dorsal surface of the wrist, but they can also occur in the following sites, amongst others:
- Palmar aspect of the wrist, close to the radial artery
- Palmar aspect of the base of the fingers, in communication with the underlying flexor sheath (also known as "pearl" or "seed" ganglion)
- Dorsal aspect of the terminal joints of the fingers or thumb (also known as a "mucous cyst")
What are the symptoms?
The presence of a visible and/or palpable lump is the most obvious symptom. There is not usually a history of recent injury.
Ganglions are not generally painful, although a small subset of dorsal wrist ganglia can cause wrist pain, especially when the patient places weight on an extended wrist, such as during press-ups or certain yoga postures. Paradoxically smaller dorsal wrist ganglions, which may be palpable but are not easily visible, more often seem to cause pain. Occasionally larger examples of both dorsal and volar wrist ganglions can simply get in the way, due to their size.
Flexor sheath "seed" ganglions are also not painful at rest, but because of their position can cause pain when gripping objects forcefully.
Mucous cysts are not in themselves painful, but the underlying terminal finger joint (DIP joint) is often arthritic, and therefore may be a source of pain. Occasionally they can expand to a size where the integrity of the overlying skin is threatened.
How are they Diagnosed?
Very often the diagnosis is clear on examination of the hand. X-rays can be helpful to look for associated osteoarthritis (degeneration) of underlying joints, particularly in the case of finger ganglions. An ultrasound scan can be helpful at times to confirm the diagnosis. An MRI of the wrist may be required in two scenarios - to confirm the suspicion of a ganglion that is barely palpable, but is causing wrist pain (also allowing some other causes of wrist pain to be ruled out), or if there is a suspicion of an underlying wrist (scapholunate) ligament injury.
How are they treated?
The treatment varies depending on the site of the ganglion, associated symptoms and the presence of underlying joint disease. Very often however, it is entirely appropriate not to pursue any active treatment at all, particularly as approximately 50% percent of wrist ganglions will spontaneously regress.
- Dorsal wrist ganglions
- Aspiration of the ganglion (drawing out the fluid with a syringe and needle) may be attempted under local anaesthetic, if it is easily palpable. This procedure is usually at least partially successful in reducing the size of the wrist lump, but its main drawback is the high recurrence rate of over 50%.
- In the case of very small ganglions, it can be useful to have this procedure combined with injection of a small amount of steroid under ultrasound scan guidance. Mr. Gidwani can arrange for this to be carried out by a consultant radiologist.
- Surgery for dorsal wrist ganglions is a last resort, and can be carried out either under general anaesthetic or "regional block", where the relevant arm is numbed by the injection of local anaesthetic (see the section on anaesthesia). A transverse skin incision is used in order to optimize scar healing. The sac is removed along with its "stalk", i.e. the connection to the underlying joint. Despite complete removal of the ganglion, there is also a risk of recurrence after surgery of up to 20%. If there is concern about a possible wrist ligament injury, an arthroscopy can also be carried out to assess the ligaments directly.
- Palmar wrist ganglions
- It is less common to aspirate these swellings as they are often close to the radial artery. Nevertheless, if the swelling is large and the position of the artery can be accurately determined, it is possible. Surgical excision allows direct visualisation of the sac and artery, but there is still a risk of damage to the artery. If the diagnosis is clear and the lump is not causing symptoms, it is reasonable to leave it alone.
- Seed ganglions
- These small ganglions on the flexor sheath of the fingers can often be treated by injection with a small volume of local anaesthetic, which effectively bursts the ganglion. If this is unsuccessful, if it recurs, or if the ganglion is too small to reliably enter with a needle, and is symptomatic, then surgical excision is warranted.
- Mucous cysts
- These small ganglions often catch or get in the way, and can expand to a size where the overlying skin is stretched to become very thin. If removal is required, this may need to be combined with a "skin flap" - i.e. rotating some skin of more normal thickness into the defect that is created by excision of the cyst and its overlying, thinned skin.
Mr. Gidwani will be able to give you more detailed information during your consultations, regarding the pros and cons of surgery, and the post-operative care.