Mucous Cyst (Fingertip Ganglion)
Mucous cyst is a small ganglion, fluid-filled sac that forms on the finger, typically between the last joint and the fingernail (Pictures 1 and 2). The cyst is attached to the joint by a stalk and is almost invariably caused by an underlying joint osteoarthritis. Even a successful removal of mucous cyst may therefore, not abolish pain entirely, but it usually alleviates it markedly especially if painful, arthritic bony spurs of the joint are cleared at the same time.
We do know that mucous cysts are typically found in patients with osteoarthritis, but why exactly they develop remains unknown.
One theory suggests that mucous cysts are formed when connective tissue degenerates (wears away). The leftover collagen is thought to collect in pools, and the pools form cysts. Fluid in the cyst sac (the same one that lubritates the joint) seems to move in one direction only – from the joint into the cyst, but not the other way hence its gradual, slow increase in size.
A mucous cyst is typically visible just under the skin that surrounds the nail. Bigger ganglions tend to cause thinning of the overlying skin which becomes almost a ‘see through’ thin (Picture 2,3). As the ganglion continues to grow and becomes more prominent, it frequently gets caught which can elicits a lot discomfort. It may be painful, but underlying arthritis more than the ganglion itself, usually causes this pain. Patients should therefore, not be surprised if even after successful ganglion removal some discomfort remains. A groove in the fingernail is very emblematic and results from nail root (germinal matrix) compression by the cyst.
Is usually very straightforward and unambiguous. If significant arthritis is suspected, X-rays might be required to ascertain degeneration related to osteoarthritis – joint space narrowing and/or bone spurs and irregularities which might need addressing at the time of cyst removal.
Mucous cysts do not need to be treated – observation is sufficient for majority of lesions. Spontaneous disappearance is however, only seen in very small, tiny ganglions, not long standing, larger ones.
Surgery should be reserved for symptomatic lesions – steady enlargement, infections, recurring discharges, pain, repeat traumas etc.
Sometimes a mucous cyst ruptures spontaneously. Rupture creates a path into the joint where bacteria could enter and cause a serious infection inside the joint. When this happens, antibiotics are applied over the ganglion, finger is wrapped in a dressing and oral antibiotics are prescribed. If the joint develops an infection despite these steps, surgery is required. Repeated ruptures are best treated surgically in order to reduce the risk of infections and further inconveniences.
Needle puncture is one option (although not my favourite). It allows partial drainage of the gelatinous filling and deflation of the cyst. Aspiration is rarely possible as ganglion filling is very viscous and usually too thick even for large needles. Aspiration usually has less than a 50 % success rate as it does not remove the sac nor it addresses underlying arthritis which causes ganglion in the first place.
Personally, I am usually reluctant to offer patients needle punctures as those do not address the problem, yet expose patients to unpleasant intervention and conversion of “closed” abnormality into “open” one, exposed to infection. If and when anything needs to be done, then radical, yet meticulous surgical removal of the cyst at least, offers a chance of eradicating problem permanently.
The most permanent solution is surgical removal (excision) of the cyst and its connection to the joint. This procedure also allows cleaning/washout (debridement) of the arthritic joint and its bony spurs which leads to significant pain relief. If the skin on the finger is too closely attached to the cyst, and/or becomes very thinned by ganglion enlargement, it should be removed together with the ganglion. Defect can then be covered with a small skin graft or more frequently, local flap (Picture 3). All of this surgery can comfortably be done under local anaesthetic whereby only the finger is numbed.
Healthy, new, non-grooved nail growing several weeks after the surgery is a testimony of adequate removal (Picture 4). Such successful outcome is however not visible in less then 6-8 weeks from surgery.
Rehabilitation after surgery
After operation only finger is covered with dressings (Picture 5). In most cases it is mobilised with the dressings in place, straight after surgery. If more extensive work is carried out to the joint itself or large flap/graft was required, splint can be applied across the joint for 1-2 weeks. You will be advised how to exercises the finger in order to regain full motion quickly. Exercises should be continued until you can move the finger normally without pain.
Complications of surgery include infection, scar sensitivity, recurrence, stiffness and persistant nail irregularity. Even after radical surgery, a mucous cyst may reappear, though this is rare.
If you have any concerns following your surgery please contact:
Ashtead 01372 221 442; St Anthony’s 020 8337 6691; Parkside 020 8971 8000
|Hospital stay||Day care|
|Anaesthetic||Local (no starving required)|
|Surgery time||30-45 minutes|
|Wound healing||2 weeks|
|Splintage||finger splint for 1-2 weeks only if skin flap/graft required|
|Hand therapy||not required|
|Washing||from week 2|
|Time off work||1-2 weeks for office based work; 3 weeks for manual work|
|Sports and exercise||from week 2|
|Driving||from week 1|
|Full recovery||2-3 weeks|
Picture 1: Fingertip ganglion arising from the joint and compressing the nail root
Picture 2: Ganglion causing nail grooving
Picture 3: Skin defect caused by excision of the ganglion will require mobilisation of the skin from shaded area to reconstruct the defect
Picture 4: New healthy nail growing after successful surgery
Picture 5: Dressings for the first 7 days