Mucous cysts occur near the fingernail and can cause the nail to be grooved or grow irregularly. Mucous cysts are common and are not dangerous. They are not usually painful but often get knocked, and this is tender. The skin over the cyst is thin and sometimes the clear gel material can leak out of the cyst.
Mucous cysts come from the end joint of the finger or thumb and are caused by a degree of arthritis in the joint (often asymptomatic).
Mucous cysts are treated by surgical excision. This is a minor operation done under local anaesthetic. The cyst is removed with the attachment to the underlying joint. If there is unhealthy tissue at the sides of the joint, this is removed to prevent the cyst recurring. When the skin over the cyst is very thin and unhealthy it may be necessary to remove this skin and move healthy skin along the back of the finger to replace it; (a 'skin flap') this requires a longer incision along one side of the finger.
A padded dressing is used, this is removed 1 week after surgery by my hand therapist. Stitches are removed at 10-14 days after surgery. Most patients are using their hand normally by 3 weeks after surgery.