Above can be seen a "bump" on the dorsum of the hand. This is a ganglion cyst, which arises in the connective tissue of a joint capsule or tendon sheath. The extensor surfaces of the hands and feet are the most common sites, particularly the region of the wrist. They probably arise following trauma from focal myxoid degeneration of connective tissue to produce a cystic space. They may regress. If not, and they are painful, they can be excised. Below is an excised ganglion cyst that has been sectioned to reveal the thin wall and the clear, mucoid contents.