A ganglion cyst is a common, non-cancerous lump that often forms near joints or tendons. These benign growths are essentially fluid-filled sacs that can vary in size and may appear suddenly or develop gradually. While they are generally harmless, their presence can sometimes cause concern due to their appearance or location.
Understanding Ganglion Cysts
These fluid-filled lumps develop just beneath the skin, typically on or near joints and tendons. They often appear on the wrist (back or front), fingers, feet, ankles, and knees. They can range in size from as small as a pea to as large as a golf ball, sometimes even becoming invisible if very small or located deeper in the tissue.
The fluid inside a ganglion cyst is a thick, jelly-like substance similar to the synovial fluid that lubricates joints and tendons. While the exact cause remains unknown, it is thought that these cysts form when a small tear or weakening in the tissue covering a joint or tendon allows lubricating fluid to leak out and collect in a sac. Irritation or trauma to a joint or tendon is sometimes linked to their development.
Typical Duration and Spontaneous Resolution
The duration of a ganglion cyst can vary significantly, with many resolving on their own. Studies suggest that between 30% to 58% of untreated ganglion cysts may disappear over time, typically within one to two years. This process, known as spontaneous resolution, occurs when the body reabsorbs the fluid inside the cyst, especially if the connection between the cyst and the joint or tendon sheath becomes blocked.
While there is no exact timeline for spontaneous resolution, some cysts might persist for months or even years if left untreated. Factors such as the cyst’s size or a person’s activity level might influence how quickly a cyst resolves, though these influences are not definitively established. Even if a cyst goes away, it can sometimes reappear later.
Management and When to Seek Medical Advice
If a ganglion cyst does not resolve on its own or begins to cause symptoms, several management approaches exist. For cysts that are not painful or do not interfere with movement, watchful waiting may be recommended. Limiting joint movement with a splint or brace can help reduce the cyst’s size and alleviate pain, particularly if activity causes the cyst to enlarge.
When a cyst causes discomfort, pain, weakness, or nerve compression (such as numbness or tingling), more direct interventions may be considered. A common procedure is aspiration, which drains fluid from the cyst with a needle. While aspiration can provide temporary relief, recurrence rates can be high (69% to 75%). Surgical excision, removing the cyst and its “root,” offers a more definitive solution, though recurrence is still possible (0% to 31.2%).
It is advisable to consult a doctor if a new lump appears, even if it is not causing symptoms, to ensure it is indeed a ganglion cyst and not another type of growth. Medical advice should be sought promptly if the cyst is painful, growing rapidly, interfering with joint movement, or causing symptoms like numbness, tingling, or muscle weakness. These symptoms indicate that the cyst might be pressing on surrounding nerves or tendons, requiring professional evaluation.