A neurofibroma is a type of nerve tumor that forms soft bumps on or under the skin. A neurofibroma can develop within a major or minor nerve anywhere in the body. This common type of benign nerve tumor tends to form more centrally within the nerve. Sometimes it arises from several nerve bundles (plexiform neurofibroma).

Symptoms are often mild or absent. If the tumor presses against nerves or grows within them, you may experience pain or numbness in the affected area.

A neurofibroma is usually noncancerous (benign). Rarely, it can become cancerous (malignant).

A neurofibroma can arise with no known cause, or it may appear in people with a genetic condition called neurofibromatosis type 1. These tumors are most often found in people ages 20 to 40 years.

Your doctor will diagnose a neurofibroma based on a physical examination, a discussion with you about your medical history, or the results of an imaging test such as a CT or MRI scan. These imaging studies can help pinpoint where the tumor is, find very small tumors, and identify what tissues are affected or nearby. Your doctor may have you undergo a PET scan to get an indication of whether it is benign. You may also have a biopsy done by a radiologist before surgery to diagnose the mass as being a neurofibroma.

Neurofibroma treatment usually isn't needed for a single, small — less than an inch (about 2 centimeters) — tumor under the skin. Neurofibroma treatment usually involves monitoring or surgery.

• Monitoring. Your doctor may recommend observation of a tumor if it's in a place that makes removal difficult or if it's small and causes no problems. Observation includes regular checkups and imaging tests to see if your tumor is growing.

• Surgery to remove the tumor. Symptoms can be relieved by removing all or part of a neurofibroma that's pressing on nearby tissue or damaging organs. What type of operation is performed depends on the location and size of your tumor and whether it's intertwined with more than one nerve. The goal of surgery is to remove as much of the tumor as possible without causing further nerve damage.

  After surgery, you may need physical rehabilitation. Physical therapists and occupational therapists can guide you through specific exercises that keep your muscles and joints active, prevent stiffness, and help restore your function and feeling.

• Clinical trials. You may be eligible for a clinical trial testing an experimental treatment.