Ganglion cysts, also known as synovial cysts or ganglia, are the most common soft tissue tumors of the wrist and hand.1 They are a common reason for patients to present to the Emergency Department. The chief complaint is usually a mild pain or ache, exacerbated by movement, and localized to a 1 to 2 cm mass on the wrist or hand. Patients may also present with concerns about a painless “lump.” Acute trauma prior to presentation is uncommon, though patients often give a history of repetitive motion at the site. The mass usually increases in size progressively over time or, occasionally, may grow rapidly over a short period. Patients presenting to the Emergency Department with ganglia may have already attempted one of several popular home remedies, including homeopathic medications or striking the cyst firmly with a large book or hammer.
Ganglion cyst aspiration is a relatively simple procedure that may be performed by the Emergency Physician. The practice of cyst aspiration has been challenged because of the high recurrence rate after the procedure.2,3 Recurrence rates of up to and even greater than 50% have been described.4,5 However, the procedure usually alleviates presenting symptoms, is occasionally curative, and is more cost-effective than referring all patients for surgical treatment.6
Ganglia are synovial cysts that originate from a joint capsule or tendon sheath. They have no malignant potential. It is unclear whether ganglia are formed by herniation of the tendon sheath, myxomatous degeneration of connective tissue, or some other mechanism. Contained within the cyst is a viscous, jelly-like fluid. Ganglia often connect with the underlying synovial cavity or tendon sheath by a stalk. Hyaluronic acid makes up all or part of the mucoid fluid.7
Ganglia are usually encountered on the dorsum of the wrist, in particular over the scapholunate ligament (Figure 105-1). They may also be found on the palmar surface of the wrist, the lateral surface of the wrist, or on the hand itself. Ganglia of the foot and ankle are less commonly seen.8 Ganglia are less commonly encountered in other areas such as the shoulder, hip, elbow, knee (including the anterior cruciate ligament), the lumbar spine, temporomandibular joint, and even the odontoid process of the cervical spine.9–11
Oblique view of the wrist demonstrating a ganglion cyst overlying the scapholunate joint.
Ganglia present as fixed or slightly movable masses that are usually solitary. Frequently characterized as smooth and “rubbery,” cysts may become more noticeable with wrist flexion. They vary in size from barely palpable to 3 cm in diameter (smaller than 1.5 cm being the norm). Tenderness is sometimes but not invariably present. Ganglion cysts will transilluminate, as they are fluid-filled. They may “disappear” over time by spontaneously rupturing or resorption.