What are nerve tumors?

Nerves are like wires that carry messages between your brain and body. Like wires, nerves have layers around them that protect them. A nerve tumor, also referred to as a nerve sheath tumor because of its location, is an abnormal growth that develops within the sheath or protective layer around the peripheral nerves, which extend from the brain and spinal cord throughout the body.

Most nerve tumors are benign (non-cancerous) but some may require treatment due to the potential for nerves to become compressed, leading to pain or loss of function. Nerve tumors generally develop within the nerve sheath, a layer of myelin and connective tissue that surrounds nerve fibers. Nerve tumor conditions, or neurofibromatoses, are typically categorized by type based on differences in location and likelihood of developing into nerve cancer. The most common types of nerve tumor conditions are neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis.

While nerve tumors tend to grow slowly, they can eventually exert pressure on nerves or the spinal cord, causing various symptoms.

Nerve sheath tumor symptoms

Nerve sheath tumors may not always show symptoms. However, when they do, the symptoms can vary depending on the location and size of the tumor. Some patients experience changes in nerve function, like weakness, or changes in sensation, such as numbness, tingling, or burning. As the tumor grows, it can create noticeable lumps or masses under the skin, which could be painful when touched. Some patients may also experience persistent pain or tingling sensations in the affected area.

If your nerve tumor is in the sciatic nerve or wrist, symptoms may mimic other conditions like lower back pain radiating down the leg (sciatica) or carpal tunnel syndrome, making it important to seek an expert provider like Penn Medicine for an accurate diagnosis.

What causes nerve tumors?

Researchers are still trying to understand why most nerve sheath tumors form. However, they know that genetics, having other tumors, or having had previous radiation therapy can increase the risk of developing one. Nerve tumors may develop spontaneously or be linked to genetic conditions such as neurofibromatosis (NF1 or NF2) or schwannomatosis, which cause tumors to grow on nerves throughout the body.

While most nerve sheath tumors are noncancerous, a small proportion may become cancerous, particularly neurofibromas and schwannomas. Penn Medicine researchers are working to better understand these genetic and environmental factors to shed light on the complex origins of nerve tumors and their associated risk factors.

Nerve tumor diagnosis

A tumor of the nerve tissue can either be benign (non-cancerous) or malignant (cancerous), so it’s important to have a healthcare provider who can quickly determine the nature of your tumor.

Your doctor will combine the findings from these evaluations to help determine the stage of your cancer (if your tumor is malignant) and begin crafting an effective treatment plan tailored to your individual needs.

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