A ganglion cyst is a type of cyst that is very common in the area of the hand and wrist. It is a lump that occurs adjacent to joints or tendons. Common locations are:
on the top of the wrist
the base of the finger, on the palm side
the side of the wrist
the top of the end joint of the finger
Resembling a water balloon on a stalk and filled with clear fluid or gel, the cause of ganglion cysts remains unknown. They may form when a joint or tendon is irritated or has mechanical changes, and may occur at any age.
These cysts can change in size as well as even disappear completely. They may or may not be painful, are not cancerous, nor will they spread to other areas.