2026 NF Knowledge Series: Understanding Skin Tumors in NF

During August's NF Knowledge Series, April Seliga, Director of Patient Education and Engagement at Children's Tumor Foundation (CTF), welcomed patients and families to a webinar focused on one of the most visible parts of living with NF: skin tumors.

Dr. Rebecca Brown, Associate Professor of Neuro-Oncology and Director of the NF and Schwannomatosis Program at the University of Alabama at Birmingham and Children's of Alabama, led the session. She made her goal clear from the start: to explain a complex topic in a way that is useful, understandable, and honest for people living with neurofibromatosis type 1 (NF1), NF2-related schwannomatosis (NF2-SWN), and other forms of schwannomatosis.

Watch the recording of this webinar here.

Why Skin Bumps Happen

Dr. Brown walked through the biology in simple terms. In NF1, every cell in the body starts with one working copy and one non-working copy of the NF1 gene. That alone can lead to features like café-au-lait spots, freckling, and other changes, but those are not tumors.

Skin bumps form later, when certain cells lose the second working copy too. Dr. Brown explained that Schwann cells (the cells that wrap around nerves like insulation around a wire) appear to play a central role. Once those cells lose both copies, they can begin forming tumors.

One key takeaway: these tumors are not all the same. Some are cutaneous neurofibromas on the top layer of the skin. Others are subcutaneous or intradermal, sitting deeper and sometimes causing more pain. Plexiform neurofibromas involving the skin can look different and may extend much deeper than what appears on the surface.

That variation matters. It affects pain, itching, appearance, imaging needs, and treatment choices.

The Impact Is Not Just Cosmetic

One of the strongest parts of the session was Dr. Brown's direct acknowledgment that skin bumps can affect mental health, self-image, and daily life. She described how people with NF often report anxiety, depression, embarrassment, and fear of judgment because of visible skin tumors.

She also shared that some people avoid certain clothes, feel uncomfortable in public, or have even faced harmful assumptions from others. For affected and unaffected community members alike, that was an important reminder: visible symptoms of NF are not superficial concerns. They can shape how safe, seen, and confident a person feels in the world.

What's Inside a Skin Bump Makes Treatment Harder Than It Sounds

Dr. Brown explained that skin bumps are not just a clump of one type of cell. They include tumor cells, blood vessels, inflammatory cells, itching cells, and extracellular matrix (the structural material around the cells).

That helps explain why treatment is challenging. Even when a therapy affects tumor cells, other material can remain behind. She described early findings with MEK inhibitors this way: the tumors may "deflate," but they do not appear to disappear fully.

She also described why itching can be so frustrating. The cells involved in itching can sit deep under the tumor, and creams often do not reach far enough into the skin to help much. Some doctors have tried oral medicines that affect mast cells, but those don't always help either.

What Can Be Treated Now: Surgery, Laser, and Electrodesiccation

Today, the treatments Dr. Brown described as effective are physical. In other words, the tumor has to be removed or damaged directly.

Surgical removal is one option. A doctor may remove a few tumors at a time, or in some cases more. Dr. Brown shared that the most she has removed in one sitting is 35 tumors. But scarring, healing, and limits on local anesthetic all shape what is possible.

Laser can also be used, though she said it is often more experimental and can come with pain, scarring, and regrowth.

Another option is electrodesiccation, where a small needle is placed into tumors and used to dry them from the inside. Dr. Brown said this method can treat thousands of tumors at once. Recovery is "not terribly bad," though skin lightening or darkening can happen.

Her advice was practical: find a specialist who understands NF, and that technique matters, especially for reducing scars and preventing regrowth.

When to Talk to Your Doctor

In the Q&A, Dr. Brown addressed one of the biggest practical questions: when should someone speak with a provider about a skin bump?

Her answer was straightforward. Rapid growth, new pain, or concern that a lesion could be plexiform should prompt a conversation with a doctor. She noted that cutaneous and subcutaneous neurofibromas do not typically become cancer, while plexiform neurofibromas carry a low but real risk.

She also spoke about a different kind of concern: quality of life. If a tumor catches on clothing, sits under glasses, rubs against a waistband or bra band, or makes someone want to hide their body, that is enough reason to ask about removal.

What Research Still Needs To Solve

The session made clear that progress is happening, but big gaps remain. Scientists still lack a reliable way to measure skin bump size. That may sound simple, but Dr. Brown explained why it is not. These tumors are soft, uneven, and hard to measure consistently, which makes clinical trials more difficult.

Researchers also cannot yet predict who will develop more skin bumps, how many, or which existing bumps will grow. A long-term study she cited showed that some tumors grow very slowly over time, while others may barely change.

Dr. Brown also touched on treatments under study, including the NFX-179 clinical trial testing a topical gel for cutaneous neurofibromas. The Phase 2 trial has been completed with encouraging results, and additional regulatory work is underway before Phase 3 can begin.

Click here for more information about our NF Knowledge Series webinars.

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