Ganglion cyst

The bump on this 5-year-old girl's left wrist had been gradually enlarging. The child could not remember how long it had been present. It waxed and waned and caused some discomfort when she flexed or extended her hand. She denied throbbing pain or weakness of the hand.

The nodule, located on the volar radial surface of the left wrist, was slightly firm, fluctuant, and nontender. It did not appear to be inflamed and produced no pulsations on palpation. The child had full wrist motility and no weakness of the muscles of the palm. These findings were consistent with a ganglion.

About 60% of hand and wrist tumors are ganglia, although they are less common in children than in adults. Ganglia typically develop adjacent to joints and tendons. They are most commonly located on the dorsal wrist, followed by the volar radial wrist. Although ganglia look like cysts, they are not true cysts because they lack an epithelial lining and are usually multilobulated, with a wall composed of collagen fibers. Inside is a clear, viscous mucin that contains glucosamine, albumin, globulin, and hyaluronic acid. Some theorize that breaks in the tendon sheath or joint capsule allow fluid to leak out, which irritates the surrounding tissues and results in a pseudocapsule. Another theory is that recurrent stress and trauma near a joint causes mucin production or mucoid degeneration of the tissues. However, most patients do not recall a specific inciting traumatic event.

Ganglia usually present as asymptomatic masses of months’ or years’ duration. They may wax and wane or disappear completely, only to recur with repeated joint motion. The tumors, especially when large, can cause aching wrist pain, tenderness, and interference with activity. They may compress the underlying medial or radial nerves and present with weakness or loss of sensation in the hand. The lesion is usually compressible, transilluminating, slightly mobile, and without overlying skin changes. Differential diagnoses include radial or ulnar artery aneurysms, which present with a pulsatile mass, and lipoma, which does not transilluminate or fluctuate in size.

About half of ganglia resolve spontaneously. Treatment is necessary only when the tumors cause discomfort or put pressure on tendons or nerves. Rupturing a ganglion is not recommended because it may damage surrounding structures. Fluid aspiration of dorsal ganglia results in permanent resolution in most cases. Volar ganglia usually require surgical excision because of the risk of damage to the radial artery or nerve with aspiration. This can be done under local anesthesia and results in resolution almost universally.

This child was referred to an orthopedist for further evaluation and management because she had a large cyst, greater than 2 cm, which caused her discomfort, and its appearance bothered her mother.

References:

FOR MORE INFORMATION:

• Thornburg LE. Ganglions of the hand and wrist. J Am Acad Orthop Surg. 1999;7:231-238.

• Young L, Bartell T, Logan SE. Ganglions of the hand and wrist. South Med J. 1988;81:751-760.