Noticing a lump on wrist can be concerning, particularly if it causes pain. While most wrist lumps are benign and painless, some may cause discomfort or be a sign of a more serious problem. As a sports medicine doctor, I often assess patients who are worried about a lump in wrist. What causes a lump on the wrist, and how do we find the cause? 

Common Causes of a Lump on Wrist

Ganglion Cyst 

A ganglion cyst is the most common cause of a lump on the wrist. This is a fluid-filled sac that arises from a joint or tendon sheath. It is most frequently seen on the back (dorsal) or occasionally the front (volar) side. Ganglion cysts may change in size according to activity. Generally, they are soft and compressible. While most cysts are painless, some can cause aching due to pressure on nerves, tendons and joints. 

Sometimes, ganglion cysts go away. If they don’t and grow in size, aspiration with a needle or surgery may be needed. 

Lipoma

Another potential cause of a wrist lump is a lipoma, a benign tumour of fatty tissue. Lipomas are soft, mobile, and generally painless. They are less commonly found in the wrist compared to other body areas. Occasionally, they can grow in size and cause pain from pressure on other structures. 

If the lipoma is large or painful, surgical excision may be needed. 

Carpal Boss

A carpal boss is a firm, bony lump at the base of the second or third metacarpal bones. It results from bone spur formation and is typically hard and immobile due to joint degeneration. It is often mistaken for a ganglion. 

If the carpal boss is painful, treatment may be needed. Options include ice, topical anti-inflammatories, a cortisone injection, or bony spur surgical removal. 

Tenosynovitis

Inflammation of the tendon sheath, known as tenosynovitis, may also cause swelling. In conditions like De Quervain’s tenosynovitis, the inside of the wrist becomes swollen and painful, especially with thumb movement. Overuse, repetitive strain, or inflammatory arthritis are common triggers.

Less Common Causes of a Lump in Wrist

Epidermoid cysts

These cysts are small, round, firm lumps beneath the skin, often arising after trauma. They occur when a penetrating wound or deep cut pushes cells from the skin’s surface into the deep layers of skin. The immune system responds to these skin cells and surrounds them with a waxy material called keratin. 

Treatment depends on symptoms. A cortisone injection may help an inflamed cyst. If the cyst becomes enlarged, drainage or surgical excision may be needed. 

Giant Cell Tumour

Tenosynovial giant cell tumours are benign, growing on joints in the hands, arms, or legs. They are the second most common tumours of the hand. They are also called giant cell tumours of the tendon sheath. They are similar to a tumour in the large joints called PVNS or pigmented villonodular synovitis. 

Rheumatoid nodules

Inflammatory arthritis, such as rheumatoid arthritis, can lead to nodules or soft tissue swelling around the joints.

Bone tumour

Tumours may cause a lump on the wrist, particularly if it is painful, rapidly growing, or associated with neurological symptoms.

Clinical Assessment of a Lump in the Wrist

A detailed history is the first step in evaluating a patient with a lump in the wrist. Important questions include when the lump first appeared, how it has changed over time, whether it is painful, and whether it interferes with wrist movement or strength. A history of repetitive activity, trauma, or systemic illness may give clues to the diagnosis.

The physical examination involves observing the location and size of the lump, assessing whether it is firm or soft, mobile or fixed, and determining whether it is tender to touch. Lipomas are soft and mobile, while carpal bosses are hard and bony. The surrounding joints, tendons, and nerves are also assessed for signs of inflammation or restriction in mobility.

If there is any concern about nerve involvement, such as numbness, tingling, or weakness, special attention is paid to possible signs of nerve entrapment. Crepitus, restricted motion, or local heat may suggest active inflammation or joint pathology.

Investigations for a Lump on the Wrist

In many cases, clinical examination provides a good indication of the cause. However, imaging can help confirm the diagnosis. 

Ultrasound is a quick tool for evaluating a lump on the wrist. It helps differentiate between cystic and solid masses. It is invaluable in diagnosing ganglion cysts, lipomas, and tenosynovitis.

X-rays are used to examine underlying bones and joints. They can detect a carpal boss, arthritic changes, or calcified masses. 

When the diagnosis is unclear or if the lump is deep or painful, an MRI can provide detailed soft tissue imaging. It is especially beneficial for suspected serious tumours, ganglion cysts, or masses that extend into deeper compartments of the wrist.

In certain cases, aspiration or biopsy may be required for histological examination if cancer is suspected. 

When to Seek Further Evaluation

Most lumps on the wrist are benign and do not require urgent treatment. However, medical assessment is essential if the lump grows rapidly, is at rest, is associated with night pain, or causes numbness or weakness. Any lump that recurs after previous aspiration or removal should also be reassessed. 

Other Frequently Asked Questions About a Lump on Wrist 

Can carpal tunnel cause a lump on my wrist? 

Not usually. Median nerve compression can occasionally occur because of a cyst or mass in the carpal tunnel, although it is not common. 

Is lump on wrist cancer? 

The majority of lumps in the wrist are not cancerous. However, worrying features that might suggest cancer include increasing rest and night pain and rapid growth of the lump. 

Why is there a bony lump on my wrist? 

A bony lump on the wrist is often caused by a common bony spur called a carpal boss. It is usually located at the base of the second or third finger. 

Final word from Sportdoctorlondon regarding lump in wrist 

A lump on the wrist is a common presentation in sports medicine. While many are due to benign conditions such as ganglion cysts, lipomas, or tendon sheath inflammation, it is important to assess each case thoroughly. Through a combination of clinical examination and targeted imaging, an accurate diagnosis can usually be made. If you notice a lump on your wrist, particularly if it is painful, increasing in size, or interfering with your daily activities, it’s important to have it assessed by a doctor. 

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