A ganglion cyst in a fluid filled bump that can occur at many locations throughout the hand or wrist. The most common locations include the back of the wrist, the palm side of the wrist, along the tendons that bend the fingers (volar retinacular cyst) or along the finger joint nearest the nail (mucous cyst).
The cause is often unknown, but can be due to underlying joint or tendon irritation, subtle injuries, or arthritis. The cyst acts like a balloon that fills up with thick, jelly-like fluid from a nearby joint or tendon.
A ganglion cyst can often be diagnosed on physical exam, as they characteristically occur in predictable locations, are often round or oval, are oftentimes soft, and allow light to easily pass through them (trans-illuminate).
Ganglion cysts can be safely observed, especially if they are not causing any pain or limitations. They are not cancerous and do not spread. If they are causing pain, limiting function or are otherwise unacceptable, they can be treated via various methods depending on the location.
Splint to minimize discomfort
Cysts on the back side of the wrist can be aspirated (fluid drawn out from them with a needle). Unfortunately, if the stalk of the balloon still communicates with the joint, it can refill ~50% of the time. Aspiration is not usually offered if the cyst is on the palm side of the wrist and close to the radial artery
Wrist ganglion cysts can be dissected from surrounding tissues and safely removed in the operating room. While aspirating the fluid from a cyst is akin to pulling the top off of a weed, surgically removing a cyst is akin to pulling a weed out by its root. Recurrence rates are low, but can occur.
Volar Retinacular Cyst
Aspiration/rupturing with a needle
If a volar retinacular cyst recurs after an attempt at aspiration and is causing discomfort when holding things in the palm (like a pebble inside your shoe), they can be surgically removed with an acceptably low recurrence rate.