History and Physical Examination
Ganglions are tumors that present adjacent to joints or tendons. The most common sites for ganglions are the dorsal aspect of the wrist near the scapholunate (SL) joint (60-70%; see the image below), the volar wrist near the radioscaphoid joint or the pisotriquetral joint (18-20%), and the volar retinaculum between the A1 and A2 pulleys (10-12%). Mucous cysts occur over the dorsal digit at the level of the distal interphalangeal (DIP) joint.
Typical appearance of dorsal ganglion cyst.
Other sites include the carpometacarpal (CMC) joint, the extensor tendons (especially associated with the first dorsal compartment), the carpal tunnel, and the Guyon canal. Ganglions may also arise within bone; these are called intraosseous ganglion cysts.
Ganglions are usually minimally symptomatic. However, depending on the location of the cyst, patients may present with a myriad of symptoms, such as dull aching pain, change in size, spontaneous drainage, and sensory nerve dysfunction. Each type of ganglion is associated with a particular set of symptoms.
Dorsal wrist ganglion
Dorsal wrist ganglions typically present in proximity to the SL interosseous ligament. Approximately 75% of these ganglions are connected to the radiocarpal joint through a stalk from the SL ligament. Some ganglions may present at a site distant to the SL ligament, but they are attached to the ligament by a long pedicle. Careful palpation over the cyst and pedicle often reveals the extent of the cyst and the direction in which it is traveling. Most are asymptomatic masses that change in size.
Some patients may present with pain and tenderness due to compression of the posterior interosseous nerve (PIN) or the superficial radial nerve. The mass itself is compressible, subcutaneous, transilluminating, and slightly mobile without associated skin changes.
Occult dorsal ganglion
Patients with occult dorsal ganglions can present with the same symptoms as those with dorsal ganglions without a clinically evident mass. These ganglions are small and not palpable. Patients often experience pain, and these lesions may go undiagnosed for extended periods. [11]
Volar wrist ganglion
Two thirds of volar wrist ganglions come from the radioscaphoid joint, the remaining third from the scaphotrapezial joint. They rarely occur at the pisotriquetral joint. The cyst usually appears between the radial artery and the flexor carpi radialis (FCR). The cyst appears small clinically, but considerable extension may be found at the time of surgery. These ganglions have been found to track along the thenar muscles or along the FCR; they may extend into the carpal tunnel, and they have multiple appendages intertwined with the radial artery.
Patients present with pain or tenderness at the site of the ganglion and a palpable cyst. They may have sensory symptoms (palmar cutaneous branch of the median nerve) or, less commonly, motor nerve dysfunction.
Volar retinacular ganglion
Volar retinacular (flexor tendon sheath) ganglions arise from the A1 or A2 pulley of the flexor tendon sheath and present as a small (3-10 mm), firm, tender, and mobile mass near the proximal digital crease or the metacarpophalangeal (MCP) joint. The mass does not move with the tendon. Patients may have associated paresthesias of the involved digit secondary to pressure on the digital nerve. The lesion may also be associated with stenosing tenosynovitis. The diagnosis is made on the basis of physical examination findings.
Mucous cyst
The mucous cyst may be heralded by a groove in the nail bed and usually presents as a 3- to 5-mm cyst eccentrically located at the DIP between the dorsal distal joint crease and the eponychium. The mass is firm, is minimally mobile, and can be transilluminated. Mucous cysts are associated with Heberden nodes and osteophytes. A mucous cyst may be ruptured on presentation.
Carpometacarpal boss
A CMC boss is not a true ganglion cyst but a large spur that develops most frequently at the base of the second and third CMC joints in response to osteoarthritis. It appears as a firm, bony, nonmobile, tender mass on the dorsum of the hand. Many patients are asymptomatic; others may experience dull aching pain. A palpable ganglion is associated with a boss in 30% of cases. Some consider trauma to be the cause of the lesion.
Proximal interphalangeal joint ganglion
A proximal interphalangeal (PIP) ganglion is similar to a mucous cyst of the DIP. A 3- to 5-mm mass arises along either side of the extensor tendon at the PIP joint. Usually, the mass pierces through the oblique fibers between the central slip and the lateral band. Patients may present with pain and limited range of motion.
Extensor tendon ganglion
An extensor tendon ganglion primarily occurs dorsally over the metacarpal joints as a subcutaneous mass. It can be tender and cause a dull ache, as well as snapping of the tendon with motion.
Dorsal retinacular ganglion
A dorsal retinacular ganglion lies within the first dorsal compartment and often is associated with de Quervain stenosing tenosynovitis. The ganglion is attached to the first dorsal extensor compartment.
Carpal tunnel ganglion
Carpal tunnel ganglions can arise within the carpal tunnel, compressing the median nerve and causing carpal tunnel syndrome. Some of the volar wrist ganglions have been known to extend into the carpal tunnel as well. [12]
Ulnar canal ganglion
Ganglions within the Guyon canal can cause compression of the ulnar nerve, causing sensory and motor disturbances. These ganglions seem to arise from the hamate and travel through the hypothenar muscles to the canal. They can cause atrophy of the interosseous muscles by compressing the motor branch of the ulnar nerve. When suspected, these ganglions should be removed early to prevent permanent damage.
Intraosseous ganglion cyst
Intraosseous ganglions represent rare incidental radiographic findings. They can, however, be a cause of dull, aching wrist pain. In such situations, all other possible diagnoses should be pursued before an intraosseous ganglion is diagnosed as the source of the wrist pain. The scaphoid and lunate are most commonly affected. Interosseous ganglions also are known to occur in the other carpal bones, metacarpals, phalanges, and distal ulna. They may have an etiology distinctly different from that of soft-tissue ganglions. [13]
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Typical appearance of dorsal ganglion cyst.
