Abstract
Hand and wrist ganglia account for 50% to 70% of all hand masses. Ganglia are benign, mucin-filled cysts found in relation to a joint, ligament, or tendon. Hand and wrist ganglia are usually symptomatic masses, often presenting with cosmetic rather than functional complaints. A wide variety of treatment options exist, from simple conservative measures to surgical resection.
Definition
Hand and wrist ganglia account for 50% to 70% of all hand masses. A ganglion is a benign, mucin-filled cyst found in relation to a joint, ligament, or tendon, first appreciated by Hippocrates. Hand and wrist ganglia are usually dorsal surface, asymptomatic masses, which often present with cosmetic rather than functional complaints. They are usually benign masses occurring in the second to fourth decades, although they may be atypical presentations of more ominous pathology, such as synovial sarcoma, extra-skeletal chondrosarcoma, avascular necrosis, or venous or arterial aneurysms of the wrist. They are typically filled from the joint through a tortuous duct or “stalk” that functions as a valve directing the flow of fluid. The mucin itself contains high concentrations of hyaluronic acid as well as glucosamine, albumin, and globulin. When it is used to describe ganglia, the term synovial cyst is a misnomer because ganglion cysts do not contain synovial fluid and are not true cysts lined by epithelium, but rather by flat cells. The etiology of ganglia remains a mystery, although many think that ligamentous degeneration or trauma plays an important role.
By far, the most common location for a ganglion is the dorsal wrist ( Fig. 32.1 ), with the pedicle arising from the scapholunate ligament in virtually all cases. Only 20% of ganglia are found on the volar wrist ( Fig. 32.2 ), with the most common site at the volar wrist crease between the flexor carpi radialis and abductor pollicis longus at the scaphotrapezoid joint. Alternatively, ganglia can occur near the joints of the finger. One subtype of hand-wrist ganglia is the “occult” cyst, which is not palpable on physical examination.
Ganglion cysts occur more commonly in women, usually between the ages of 20 and 30 years. However, they can develop in either sex at any age. Ganglia of childhood usually resolve spontaneously without sequelae, although somewhat controversial surgical options have shown good long-term outcomes as well. The most commonly seen ganglion of the elderly, the mucous cyst, arises from an arthritic distal interphalangeal joint ( Fig. 32.3 ), which is most commonly associated with osteoarthritis of the joint.
Other common types of ganglia in the hand include the retinacular cyst (flexor tendon sheath ganglion; Fig. 32.4 ), proximal interphalangeal joint ganglion, and first extensor compartment cyst associated with de Quervain tenosynovitis. Less common ganglia include cysts within the extensor tendons or carpal bones (intraosseous) and those associated with a second or third carpometacarpal boss (arthritic spur). Rarely, ganglia within the carpal tunnel or Guyon canal can produce carpal tunnel syndrome or ulnar neuropathy, respectively, the complexity of which can be evaluated with noninvasive nerve conduction studies.
The direct cause of ganglion cyst formation remains unknown. However, an increased incidence in typists, musicians, surgeons, and draftsmen seems to suggest an association with repetitive activities. Interestingly, there is no increased risk in heavy laborers, who bear a greater load on their wrists. Wrist instability has also been discussed as both a possible cause and an effect of the disease. Overall, there is some history of trauma in 10% to 30% of people presenting with the disease, but with the commonality of bumps and bangs to the hands we all get in daily life, it is hard to draw a direct causative correlation.
Symptoms
Patients with a wrist ganglion usually present with a painless wrist or hand mass of variable duration. The cyst may fluctuate in size or disappear altogether for a time. Pain and weakness of grip are occasional presenting symptoms; however, an underlying concern about the appearance or seriousness of the problem is usually the reason for seeking medical attention. The pain, when present, is most often described as aching and aggravated by certain motions. With dorsal wrist ganglia, patients often complain of discomfort as the wrist is forcefully extended (e.g., when pushing up from a chair). Interestingly, dorsal wrist pain may be the principal complaint of patients with an occult dorsal wrist ganglion, which is not readily visible. The wrist pain usually subsides as the mass enlarges.
Retinacular cyst patients usually complain of slight discomfort when gripping, such as a racket handle or milk jug. Patients whose complaints of pain are primarily related to de Quervain tenosynovitis (see Chapter 28 ) may notice a bump over the radial styloid area and have the classic Finkelstein sign. Pain with grip may be a complaint of patients with a carpometacarpal boss. On occasion, the digital extensor tendons may jump over the cyst with radioulnar deviation. Mucous cysts can drain spontaneously and can also produce nail deformity, either of which may be a presenting complaint. Symptoms identical to those of carpal tunnel syndrome will be noted by patients with a carpal tunnel ganglion. A ganglion in the Guyon canal will produce hand weakness (due to loss of intrinsic function) and may produce numbness in the ring and small fingers.
Physical Examination
The importance of a complete hand and wrist orthopedic, vascular, and neurologic exam cannot be overstated. This includes observation for muscle wasting, neurosensory loss, and vascular compromise. Ganglia are typically solitary cysts, although they are often found to be multiloculated on surgical exploration. They are usually mobile a few millimeters in all directions on physical examination. The mass may be slightly tender. When the cyst is large, transillumination (placing a penlight directly onto the skin overlying the mass) will help differentiate it from a solid tumor.
The classic location for a dorsal wrist ganglion is ulnar to the extensor pollicis longus, between the third and fourth tendon compartments, or directly over the scapholunate ligament. Bilateral or symmetric presentation should trigger considerations of more atypical histology from a migratory embryological origin. However, ganglia may have a long pedicle that courses through various tendon compartments and exits at different locations on the dorsal wrist or even the volar wrist, and multiple review articles suggest that gross exam usually underestimates the size and complexity of the cyst. When the ganglion is small, it may be apparent only with wrist flexion. Wrist extension and grip strength may be slightly diminished. Dorsal wrist pain and tenderness with no obvious mass or instability should suggest an occult ganglion. Examination of the wrist should be carried out, considering non-ganglia associated conditions. Extensor retinacular tendonitis, extensor carpi ulnaris dislocation, and pseudotumor tuberculosis of the wrist have all been seen and documented initially as ganglia. Volar ganglia occur most commonly at the wrist flexion crease on the radial side of the flexor carpi radialis tendon but may extend into the palm or proximally, or dorsally into the carpal tunnel. They can involve the radial artery, complicating their surgical removal. They may seem to be pulsatile, although careful inspection will demonstrate that the radial artery is draped over the mass.
Retinacular cysts are usually not visible, but are palpable as pea-sized masses, typically located at the volar aspect of the digit at the palmar digital crease. They are adherent to the flexor tendon sheath and do not move with finger flexion. Alternatively, intratendinous ganglia are distinguished by the fact that they move with finger motion.
Mucous cysts are located over the distal interphalangeal joint, and the overlying skin may be quite thin and they may be mistaken for warts and overlap with Heberden nodules. Nail plate ridging deformity is an associated finding. Spontaneous drainage and with septic distal interphalangeal joint arthritis are not uncommon. Proximal interphalangeal joint ganglia are located on the dorsum of the digit, slightly off midline. Ganglia associated with carpometacarpal bosses produce tender prominences on the dorsum of the hand distal to the typical location for a wrist ganglion.
An important sign on physical examination, especially in planning for surgery, is compression of the median or ulnar nerve or of the radial artery. An Allen test should be performed before surgery to evaluate radial and ulnar artery patency, particularly in the case of a volar cyst ( Fig. 32.5 ).
