Wrist Bump: Most Likely Diagnosis and Evaluation
A bump on the wrist is most commonly a ganglion cyst, which arises from myxomatous degeneration of periarticular tissue and represents the most frequent soft tissue mass in this location. 1, 2
Initial Diagnostic Approach
Start with plain radiographs (posteroanterior, lateral, and oblique views) to exclude bony pathology, arthritis, or alignment abnormalities before attributing the bump to soft tissue pathology. 1, 3
- Radiographs will identify any underlying bone lesions, fractures, or arthritic changes that could present as a palpable mass 1
- The lateral view can demonstrate soft-tissue swelling and help localize the lesion 3
- Most ganglion cysts will not be visible on radiographs, but this step is essential to rule out other causes 1
Physical Examination Findings
Focus your examination on these specific features:
- Location matters: Ganglion cysts most commonly occur on the dorsal wrist (60-70% of cases) or volar radial wrist 2, 4
- Transillumination: Ganglion cysts characteristically transilluminate with a penlight, distinguishing them from solid masses 4
- Consistency: The mass should feel firm but slightly compressible, and may fluctuate in size 2
- Mobility: Ganglion cysts are typically mobile but may have some attachment to underlying joint capsule or tendon sheath 4
Advanced Imaging When Needed
If radiographs are normal and the diagnosis remains uncertain, ultrasound is the most appropriate next study for evaluating wrist soft tissue masses, with accuracy similar to MRI for ganglion cysts. 1
- Ultrasound can definitively diagnose ganglion cysts and distinguish them from other soft tissue masses 1
- US can also guide aspiration if therapeutic intervention is desired 1
- MRI without contrast is reserved for cases where US is inconclusive or when the mass has atypical features suggesting other pathology (lipomas, hemangiomas, nerve sheath tumors) 1
Differential Diagnosis to Consider
Beyond ganglion cysts, evaluate for:
- Tendon disorders: Tenosynovitis or tendon sheath masses, particularly if the bump is along a tendon course 1
- Carpal boss: A bony prominence at the base of the second or third metacarpal, which would be visible on radiographs 1
- Inflammatory conditions: Rheumatoid nodules or synovitis if there are systemic symptoms or multiple joint involvement 1, 5
- Intraosseous ganglion: Rare subchondral lesions that erode bone, visible on radiographs as lytic lesions 2
Critical Red Flags
Refer urgently if you identify:
- Rapid growth or pain at rest: Suggests possible neoplastic process requiring MRI evaluation 1, 4
- Fever, erythema, or warmth: Indicates possible infection requiring aspiration 1, 5
- Fixed, hard mass: Atypical for ganglion cyst and warrants MRI to exclude solid tumor 4
- Neurological symptoms: Suggests nerve compression requiring advanced imaging 1
Management Pathway
For confirmed ganglion cysts:
- Observation is appropriate for asymptomatic or minimally symptomatic lesions, as spontaneous resolution occurs in up to 58% of cases 2
- US-guided aspiration can be performed for symptomatic relief, though recurrence rates are 50-70% 1
- Surgical excision is reserved for recurrent, painful, or functionally limiting cysts 2