Ganglion cysts are the most frequent cause of swelling or masses found at the wrist level. Ganglion cysts are like a little balloon made out of the joint capsule, filled with a clear, colorless, gelatinous fluid coming from the joint itself. Ganglions usually present with a single cavity but may contain multiple chambers. They remain filled because they have a one-way valve mechanism allowing for fluid to easily come in but difficult to return into the joint.
Ganglion cysts occur most frequently in women. 70% of cases occur in patients between 20 and 40 years old. In older patients, they may be associated with arthritis. Ganglions are rarely seen in children. 60-70% of ganglions occur on the back of the wrist over the scapholunate ligament and about 20% are found in the palmar side over the scaphotrapezoid joint.
Patients complain of localized wrist pain aggravated with activity and weakness during repeated use of the hand. Characteristics of a Ganglion Cyst:
- Slow growing
- Slightly fluctuant mass that initially comes and goes and in time becomes both permanent and tender
Dorsal ganglions become more obvious with wrist flexion. Cysts on exam can transmit the light of a flashlight when in the dark. This is a technique used to confirm the diagnosis.
On occasions, patients will present with pain at maximal wrist extension but no obvious mass is noted on palpation over the scapholunate joint during the physical exam. This may represent an occult ganglion cyst and an MRI may be necessary to confirm the diagnosis.