What is a Mucous Cyst?
A mucous cyst is a small, fluid-filled sac that forms on the back of the finger near the base of the fingernail. It is a form of ganglion cyst that arises from the capsule of the joint at the end of the finger, called the distal interphalangeal (DIP) joint. The cyst is attached to the joint capsule by a "stalk" that allows fluid to move into the cyst from the joint. Mucous cysts most commonly affect the index finger.
How are Mucous Cysts Diagnosed?
Mucous cysts are diagnosed by your doctor based on an examination. Usually xrays are also recommended, because the cysts are commonly associated with finger arthritis.
How are Mucous Cysts Treated?
Treatment of cysts can be conservative with observation and/or aspiration of the gel-like fluid. If the cysts become large or cause nail damage, surgery is frequently recommended.