Ganglion cyst is a benign cystic lesion originating from a joint capsule or tendon sheath, containing gel-like mucoid fluid (viscous fluid containing hyaluronic acid and glucosamine). It is the most common soft tissue tumor of the hand and wrist, comprising 50-70% of all hand/wrist masses. Most common location is the dorsal wrist (60-70%) — arising adjacent to the scapholunate ligament. Second most common is the volar wrist — lateral to the radial artery, originating from the radioscaphoid or scaphotrapezial joint. 3 times more common in women, peaking at age 20-40. On MRI, a T2-bright, thin-walled, non-enhancing cystic lesion with a stalk/pedicle extending to the joint is characteristic. US is effective for diagnosis and treatment (aspiration). Most ganglion cysts are asymptomatic requiring no treatment; aspiration or surgical excision for symptomatic ones.
Age Range
15-50
Peak Age
30
Gender
Female predominant
Prevalence
Very Common
The pathogenesis of ganglion cyst is not fully elucidated but the most accepted theory is the 'capsular defect/one-way valve' model. A defect (micro-tear) develops in the joint capsule or tendon sheath from microtrauma or degeneration → intra-articular synovial fluid seeps out through this defect unidirectionally (valve mechanism — fluid can exit but not return) → mucoid fluid accumulates in pericapsular/peritendinous area → pseudocapsule develops and cyst enlarges. Cyst contents differ from synovial fluid: high concentration of hyaluronic acid, glucosamine, and chondroitin sulfate — this viscous, gelatinous fluid requires thick needle for aspiration. The stalk/pedicle is the cyst's connection to the joint capsule and complete removal during surgical excision is critical to prevent recurrence — if stalk is left, recurrence rate rises to 20-40%. Physics basis of T2-bright cyst on MRI: cyst fluid consists predominantly of free water protons → long T2 relaxation time (~80-150 ms) → high signal on T2 sequences. However, viscous mucoid fluid may not be as bright as pure water — protein and glycosaminoglycan accumulation may partially shorten T2 producing homogeneous intermediate-high signal. On T1, cyst is usually low signal but may show mild signal increase with high protein content. No enhancement because cyst wall is fibrous pseudocapsule composed of avascular structure — no active inflammation or solid component.
Homogeneously T2-hyperintense, thin-walled, lobulated cystic lesion with stalk connection to joint capsule or tendon sheath on T2 fat-sat MRI is the diagnostic combination for ganglion cyst. Absence of enhancement and solid component confirms benignity.
On T2 fat-sat images, a homogeneously hyperintense, thin-walled, oval or multilobulated cystic lesion is seen. Cyst wall is smooth and thin (<2 mm) — irregular or thick wall raises malignancy concern. Multilobulated morphology ('cluster of grapes' or 'string of beads' appearance) is characteristic of ganglion cysts. Size varies from few mm to 3-4 cm. Most commonly found adjacent to scapholunate ligament on dorsal wrist. Intracystic signal is usually homogeneous but may be heterogeneous with hemorrhage or infection. Septa may be present — creating multilocular morphology. Axial, coronal, and sagittal planes evaluate anatomic relationships and stalk connection.
Report Sentence
Homogeneously T2-hyperintense, thin-walled, lobulated cystic lesion is noted, consistent with ganglion cyst.
On T1 images, cyst shows low-intermediate signal, lower than surrounding muscle. In ganglion cysts with high protein content, T1 signal may be slightly elevated — but not at solid component level. Stalk connection is seen as thin, low-signal tubular structure on T1 — showing connection to joint capsule or tendon sheath. On dorsal wrist, stalk originates from scapholunate ligament region, on volar from radioscaphoid or scaphotrapezial joint. On contrast T1 fat-sat, cyst contents do not enhance — wall may show very thin enhancement but no solid component. Enhancement presence suggests synovial cyst, synovial sarcoma, or other neoplastic lesions.
Report Sentence
T1-low signal cystic lesion showing stalk connection to the scapholunate region, consistent with ganglion cyst.
On B-mode US, an anechoic or hypoechoic, well-defined, thin-walled cystic lesion with posterior acoustic enhancement is seen. Simple ganglion appears homogeneously anechoic (black). Viscous ganglion cysts may be hypoechoic or show internal echoes — aspiration requires thick needle. Lobulated morphology ('cluster of grapes') also seen on US — multiple interconnected cystic areas. Stalk connection traced on transverse and longitudinal sections — thin tubular structure between cyst and joint or tendon sheath. US-guided aspiration is both diagnostic and therapeutic — recurrence rate 50-70% (because stalk cannot be removed). Compression demonstrating shape change is characteristic — solid lesions do not change shape.
Report Sentence
Anechoic, thin-walled cystic lesion with posterior acoustic enhancement on US, consistent with ganglion cyst.
No intralesional vascularity on power Doppler or color Doppler — supports benignity. In normal ganglion cyst, vascularity is minimal or absent in cyst wall and stalk. Increased vascularity in cyst wall or septa is atypical and MRI evaluation is recommended to exclude malignancy. Physiologic vascularity in surrounding normal tissues may be demonstrated — this Doppler signal should not be confused with intralesional vascularity.
Report Sentence
No intralesional vascularity on Doppler, consistent with benign cystic lesion.
On T2 images, intraosseous or deep soft tissue ganglion cyst may be seen — occult ganglions not palpable on clinical examination. Intraosseous ganglion appears as a T2-hyperintense, T1-hypointense, well-defined cystic lesion within bone marrow — sclerotic rim is typical. Most commonly in carpal bones (lunate, scaphoid) and tibial plateau. Deep soft tissue ganglions may be found around joints (popliteal fossa — differential from Baker cyst, hip — paralabral cyst associated with acetabular labral tear). MRI can detect these occult lesions without clinical suspicion.
Report Sentence
T2-hyperintense cystic lesion with sclerotic rim within bone marrow is noted, consistent with intraosseous ganglion cyst.
Criteria
Cyst on dorsal wrist originating adjacent to scapholunate ligament. Most common form (60-70%).
Distinct Features
Stalk originates from scapholunate ligament area. Most palpable — positive transillumination on exam. Spontaneous resolution 40-60%. Recurrence after aspiration 50-70%. Surgical excision recurrence 5-10% (if stalk completely removed).
Criteria
Cyst on volar wrist surface, lateral to radial artery. Originates from radioscaphoid or scaphotrapezial joint.
Distinct Features
Proximity to radial artery requires careful vascular planning for surgical excision. Allen test preoperatively (ulnar circulation adequacy). US evaluates artery-cyst relationship — risk of artery damage during aspiration.
Criteria
Cystic lesion within bone marrow with sclerotic rim. Most common in carpal bones (lunate, scaphoid) and tibial plateau.
Distinct Features
Clinically not palpable (occult). CT: well-defined lytic lesion, sclerotic rim. MRI: T2 hyperintense, T1 hypointense, no enhancement. Differential: simple bone cyst, chondral defect, geode (subchondral cyst). Curettage + grafting if symptomatic.
Distinguishing Feature
Giant cell tumor is solid showing low-intermediate T2 signal (hemosiderin) and marked enhancement — ganglion cyst is cystic, T2-bright with no enhancement. Hemosiderin blooming on T2* GRE is diagnostic for giant cell tumor.
Distinguishing Feature
Bursitis shows distended fluid-filled bursa at anatomic location with synovial thickening and surrounding edema — ganglion cyst is located outside anatomic bursa, shows stalk connection, and has no synovial thickening.
Distinguishing Feature
Synovial sarcoma is heterogeneous mass with solid component showing marked enhancement, fluid-fluid levels, and aggressive growth pattern — ganglion cyst is homogeneously cystic, no enhancement, and indolent. Synovial sarcoma may show 'triple sign' (low, intermediate, and high signal areas on T2).
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
no-follow-upGanglion cyst is a benign lesion not requiring treatment in most cases. Asymptomatic ganglion cysts are followed with observation — spontaneous resolution rate is 40-60%. For symptomatic cases (pain, functional limitation, cosmetic concern) treatment options: (1) US-guided aspiration — viscous fluid aspirated with thick needle, corticosteroid injection may follow. Recurrence rate 50-70% as stalk cannot be removed. (2) Surgical excision — complete removal of cyst and stalk (most definitive treatment). Recurrence rate 5-10% (if stalk completely removed). Arthroscopic excision as minimally invasive alternative — especially for dorsal wrist ganglions. Complications: nerve injury (superficial radial nerve branch — dorsal ganglions), tendon injury, vascular damage (radial artery proximity in volar ganglions). Old 'Bible treatment' (crushing with book) is no longer recommended — risk of fracture, nerve damage, and infection.
Ganglion cysts are generally benign and do not require treatment. In symptomatic cases, aspiration (recurrence rate 50-70%) or surgical excision (recurrence rate 10-20%) is performed. Surgical removal is preferred for cysts causing nerve or vessel compression. US-guided aspiration is safe and effective.