Ganglion cyst
A ganglion cyst is a swelling that often appears on or around joints and tendons in the hand (or sometime feet). The size of the cyst can vary over time, often becoming more inflamed if irritated.They are not generally considered harmful although can cause discomfort and/or limit movement. Frequently, the cysts will disappear over time, although in cases where they are causing problems with mobility or excessive pain they can be surgically removed.
This article is a stub. You can help Wikipedia by [ expanding it].