Schwannoma Puzzle

Three medical doctors have published a case report of a 40-year-old Italian man who developed a tumor in his thigh, near where he “habitually” kept his smartphone in a trouser pocket.

The case was published at the end of August in Radiology Case Reports, a peer-reviewed, open access journal.

The tumor, a painless mass, gradually expanded in the man’s left thigh over a period of six months, they wrote. It grew in his Schwann cells and is known as a schwannoma. It was benign. 

Schwann cells play an important role in the functioning of the peripheral nervous system. They make up the myelin sheath, which insulates nerve fibers and helps speed the conduction of electrical impulses. They are present in most organs of the body —whether of mice, rats or humans.

The authors —two Italians and one Moroccan— acknowledge that they “cannot establish a definitive causal relationship” between the tumor and the placement of the phone in the trouser pocket, but they state that the case underscores the “need for further research.”

Second Report in Preparation

Microwave News has learned of a second, similar case, as yet unpublished, also in Italy. It deals with a schwannoma that developed in a woman’s forearm, close to a pocket where she put a cell phone while doing sports for about one hour a day, every day for more than ten years.

This latter case is being written up by Fiorella Belpoggi, the former scientific director of the Ramazzini Institute outside Bologna. She retired in 2019 but continues to be one of the institute’s scientific advisors. Belpoggi ran Ramazzini’s long-term RF exposure study, which found schwannoma of the heart among exposed rats (more here).

The U.S. National Toxicology Program (NTP) saw malignant schwannoma of the heart among its RF–exposed rats. This is what led to the now well-known conclusion that there is “clear evidence” of cancer following RF exposure.

The NTP found schwannomas in a variety of glands (pituitary, salivary and thymus), as well as the trigeminal (cranial) nerve and the eye. The NTP saw schwannomas in the uterus, ovary and vagina of female rats.

The fact that both Ramazzini and the NTP bioassays showed the same type of obscure tumor led some observers to opine that “more than a coincidence” was at work (more here).

Acoustic Neuroma Is a Type of Schwannoma

An acoustic neuroma is a tumor on the nerve connecting the ear to the brain. It too is a schwannoma. It has long been associated with cell phone use. A link was first reported by Sweden’s Lennart Hardell in 2002, and supported by Maria Feychting of the Karolinska Institute and other members of the Interphone project. (More about this history here). Feychting later changed her mind and became an outspoken critic of any cell phone tumor risk.

In 2012, the Supreme Court of Italy affirmed a workers’ compensation award to a businessman who developed a tumor of the trigeminal nerve after using a cell phone for 12 years. (A similar award, also in Italy, here.)

So Are Gliomas

What is not widely recognized is that the brain’s glial cells are related to Schwann cells, as explained by the NTP in its final report of its RF project:

“Schwann cells are similar to glial cells in the brain in that they are specialized supportive cells whose functions include maintaining homeostasis, forming myelin and providing support and protection for neurons of the peripheral nervous system.”

Glial cells are in the central nervous system; Schwann cells are in the peripheral nervous system. They serve similar functions.

Gliomas, tumors of glial cells, are the other type of tumor most often associated with cell phone use.

Schwannoma in Muscle Tissue

A schwannoma “can occur anywhere in your body, at any age,” according to the Mayo Clinic: In an arm or leg, it manifests as a slow-growing, painless lump. It is rarely cancerous, but can lead to nerve damage and loss of muscle control.

The Cleveland Clinic states that schwannomas are usually found among people between the ages of 50 and 60 years —and rarely in children. They are uncommon, affecting fewer than 200,000 people each year in the U.S.; about 60% of benign schwannomas are vestibular schwannomas (acoustic neuromas).

In most cases, according to the Cleveland Clinic, schwannomas “happen randomly for unknown reasons.”

A team from Korea presented a case report of a schwannoma in the muscles of a 79-year-old man’s back in the journal Nerve in 2020. The tumor, when removed, measured 2.0 × 2.0 × 3.5 cm. The report is open access.

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For other reasons to keep a phone out of your pocket, see:

Colorectal Cancer Soaring in Young Adults; Are Smartphones in the Mix?

Keep That Phone Out of Your Trouser Pocket!