Neuroma In The Hand: Diagnosis And Management Strategies

Introduction

A neuroma is a non-cancerous tumour of nerve cells (neurons) which can arise after damage to nervous tissue, after injury to a nerve during surgery, after amputation, or after traumatic injury. A neuroma may also form as part of other health conditions unrelated to a nerve injury, as a common cause of hand pain. Nerves exist throughout the entire body, and they function to send and receive signals from the brain. A nerve in the hand is referred to as a peripheral nerve as it is located outside of the central nervous system of the brain and spinal cord. A single peripheral nerve consists of many bundles of nerve fibres (fascicles). The fascicles are covered in a layer of connective tissue called the perineurium, which holds the nerve fibres together. When the perineurium becomes damaged, the neurons are able to escape from their normal organised structure and are exposed to the surrounding tissue. 

These injured nerve cells regenerate incorrectly over time, resulting in the formation of a disorganised collection of nerve cells, blood vessels and scar tissue - a neuroma. These regenerated nerve cells in the neuroma can transmit signals to the brain, which can be interpreted as pain, tingling or numbness. If the symptoms are severe, a neuroma can drastically affect the lives of those who are affected. 

Both surgical and non-surgical methods for managing the condition exist. Your healthcare provider should discuss these with you after performing an extensive history and physical examination.

Causes and risk factors

Potential causes

The causes of a neuroma of the hand include:¹

• Previous hand surgery
• Injury to a nerve in the hand
• Previous amputation of a finger 
• Genetic conditions e.g. Neurofibromatosis, Multiple endocrine neoplasia 2B

Risk factors

The risk of neuroma formation is present whenever an invasive surgical procedure is performed due to the potential for damage to a nerve occurring during surgical exploration.

Signs and symptoms

Common signs and symptoms

Some neuromas do not cause any pain at all.³ Other times, neuromas cause neuropathic pain. 

One symptom of neuropathic pain is allodynia. This is pain which occurs without a cause. Pain in response to a non-painful stimulus - hyperalgesia- is also a component of neuropathic pain. This can include pain in response to gentle pressure, touch, brushing of the skin or temperature fluctuations.¹ 

Other symptoms of hand neuromas include:³ 

• A hard lump, which can be felt on examination.
• Pain or tingling when light pressure is applied to the area.
• Loss of sensation.

Differentiation from other hand conditions

Many conditions of the hand can cause pain, so a correct diagnosis is essential to ensure that the most effective treatment options are explored. 

In the case of hand neuroma, the physician is usually able to identify the diagnosis through the history and physical examination without the need for imaging.¹

Diagnosis

Diagnostic procedures

In most cases of hand neuroma, the diagnosis is found through history and physical examination. Imaging is not typically required unless the diagnosis is vague or uncertain. 

Some clinicians may inject a small amount of local anaesthetic near the neuroma. The pain associated with the neuroma usually reduces significantly after the injection or even goes away completely after this injection.³ 

Importance of medical history and examination

During the consultation, the healthcare provider will ask questions to gather information on the possible causes of the symptoms. If there is a history of surgery or trauma to the hand in the past, this is likely the cause of the neuroma.¹ If no such incident has occurred but the diagnosis is likely to be a neuroma, further testing may be required to identify whether there is an underlying health condition. 

Role of imaging techniques

If there is a doubt in the diagnosis, imaging may be used to exclude other causes. The imaging techniques may include X-ray scans to differentiate from a fracture. Other techniques include CT, ultrasound or MRI scans to detect malignancy, i.e. cancerous growths. 

Management strategies

Non-surgical options

Symptomatic neuromas can be treated conservatively. This means that there are options to manage the symptoms without surgical intervention. The non-surgical options for painful neuroma management include:^1,3 

• Physical therapy - e.g. massage.
• Oral analgesia e.g. opioids. 
• Antidepressant medications.
• Anticonvulsant medications.
• Ultrasound-guided steroid injections.
• Injection of local anaesthetic or topical anaesthetic patches.
• Topical capsaicin. 

These methods all have varying levels of efficacy, which can also differ between patients. 

Surgical options

There are several surgical treatments for hand neuromas. If, after 6 months, non-surgical methods fail and symptoms continue to intervene in the daily life of patients, surgery is a viable option. 

Surgical options include:^1,3

• Resection of the neuroma - This involves surgically removing the neuroma. Additionally, the performing surgeon may opt to perform a nerve repair at the same time. This is sometimes called nerve reconstruction.
• Nerve transposition into muscle - this involves the removal of the neuroma, after which the surgeon buries the nerve into a muscle with the aim of reducing the amount of nerve stimulation. In turn, this should reduce the amount of pain.
• Nerve transposition into a vein - this is similar to the previous method, but the nerve is implanted into a vein instead, e.g. the femoral vein.

Post-treatment care

Recovery process

Total recovery may not be accomplished straight away or with one treatment method alone. 

If a surgical procedure is opted for, the recovery will be dependent on many factors, including the type of anaesthetic used. Recovery from general anaesthetic is longer than local anaesthetic. If there is a post-surgical complication, the recovery process may be prolonged further. 

Rehabilitation

Rehabilitation generally depends on the method of treatment. In the case of conservative management, physical therapy may be a part of the treatment plan to help reduce the symptoms.¹ 

Prevention of recurrence

Recurrence of pain is possible even after treatment; therefore, prevention is vitally important.³  

The initial prevention of neuromas can be achieved by avoiding injury to nerves during elective procedures by the operating surgeons. If a nerve injury is found after a procedure is performed, early repair involving the re-establishment of the connection of the injured nerves may help to prevent the formation of a neuroma in the future.³ 

Complications and prognosis

Potential complications

Surgical procedures all carry a risk of postoperative complications. In the case where surgery is performed to treat the neuroma, the possible side effects include:

• Bleeding
• Infection
• Scarring

There are also risks associated with general anaesthetic. These should be discussed with your healthcare provider prior to any surgical procedure. 

Prognosis and long-term outcomes

Around 30% of neuromas do not improve with surgical management.⁴ The success of neuroma surgery is also influenced by the number of previous surgical procedures in the same area. 

If the symptoms of the neuroma return or are not resolved using a certain treatment method, a specialist should be able to advise the next course of action in managing the condition. 

There is also evidence that early intervention with analgesia (pain relief medication) reduces pain and improves the prognosis in conditions involving the hand.³ 

Summary

Hand neuromas are formed when the normal nerve function and positioning in the hand are disrupted. In some cases, they result in neuropathic pain. They can occur as a consequence of an injury to the nerve, either through trauma to the hand or a surgical procedure. The diagnosis of a neuroma should become clear after a clinician takes a full history and performs a physical examination - rarely does a scan need to be performed to confirm the diagnosis. Conservative treatment options can help to manage the painful symptoms of hand neuromas. If these techniques fail to have a significant improvement, a healthcare provider can discuss the variety of surgical options available. The outcomes of the surgery will be dependent on many factors, and recurrence is possible.