Your pathology report for ganglioneuroma

by Jason Wasserman MD PhD FRCPC
September 23, 2025

A ganglioneuroma is a rare type of non-cancerous tumor that develops from cells of the sympathetic nervous system. This is part of the body’s network of nerves that controls automatic functions such as heart rate, blood pressure, and digestion.

Ganglioneuroma is considered the most mature form in a family of tumors called neuroblastic tumors. Less mature forms include neuroblastoma (cancerous) and ganglioneuroblastoma (which has both mature and immature cells). Over time, less mature tumors can develop into a ganglioneuroma.

Where in the body do ganglioneuromas develop?

Ganglioneuromas form in areas where the sympathetic nervous system is located. They are most often found in:

• The adrenal gland (a small organ above each kidney).

• The chest (mediastinum).

• The abdomen or pelvis, along the spine.

Because they usually grow slowly, ganglioneuromas can become large and press on nearby structures, but they rarely invade surrounding tissues.

Who gets ganglioneuroma?

Ganglioneuroma is a rare condition, and its exact frequency is unknown. It is most often diagnosed in older children and adolescents, but can also occur in adults. When found in adults, an adrenal ganglioneuroma is usually discovered by chance during imaging tests done for other reasons.

What causes ganglioneuroma?

The exact cause of ganglioneuroma is not known. Doctors believe that these tumors develop when immature nerve cells (called neuroblasts) gradually mature into normal-appearing nerve cells (ganglion cells) and Schwann cells (support cells of the nervous system). This process explains why ganglioneuroma is considered the most mature and least aggressive type of neuroblastic tumor.

What are the symptoms of ganglioneuroma?

Most ganglioneuromas do not cause symptoms and are found incidentally during imaging tests for other reasons. When they do cause symptoms, these are usually related to the size or location of the tumor, such as:

• Abdominal pain or discomfort

• A feeling of fullness

• Pressure on nearby structures

• Rarely, hormonal changes occur if the tumor produces hormones (most are non-functioning and do not release hormones)

How is ganglioneuroma diagnosed?

Doctors may suspect a ganglioneuroma based on imaging studies such as CT or MRI, which often show a solid, well-defined mass. However, the diagnosis can only be confirmed after the tumor is removed or biopsied and examined under the microscope by a pathologist.

What does a ganglioneuroma look like under the microscope?

When examined under the microscope, ganglioneuromas are made up of two main types of cells:

• Schwann cells, which form bundles of supporting tissue

• Ganglion cells, which are mature nerve cells

Pathologists describe two subtypes of ganglioneuroma: maturing ganglioneuroma and mature ganglioneuroma. Both subtypes are benign (non-cancerous).

Maturing ganglioneuroma

In this subtype, the tumor contains a mixture of developing and mature ganglion cells. The developing cells may differ in size and shape and can sometimes have more than one nucleus. These cells are scattered individually or grouped in small clusters among the background of Schwann cells.

Mature ganglioneuroma

In this subtype, all of the ganglion cells are fully developed (mature). They are often surrounded by small support cells called satellite cells. Mature ganglioneuromas typically have a very orderly appearance, with Schwann cells forming bundled sheets of tissue around the ganglion cells.

In both subtypes, the ganglion cells lack the “naked nerve fibers” (neuropil) typically found in less mature neuroblastic tumors. Instead, their nerve processes are incorporated directly into the Schwann cells.

What is the difference between ganglioneuroma and other neuroblastic tumors?

Neuroblastic tumors form a spectrum:

• Neuroblastoma is composed of immature cells and is a type of cancer.

• Ganglioneuroblastoma is characterized by a mixture of mature and immature cells and may exhibit more aggressive behavior.

• Ganglioneuroma is made of mature cells and is non-cancerous.

Because of this spectrum, pathologists carefully examine tumor samples to make sure there are no areas of neuroblastoma present.

What is the prognosis for a person with ganglioneuroma?

The prognosis for ganglioneuroma is excellent. These tumors are benign and do not spread to other parts of the body. Even if the entire tumor cannot be removed, most patients do very well and do not experience long-term health problems.

Rarely, a small area of a more aggressive tumor, such as ganglioneuroblastoma, may be present within a ganglioneuroma. For this reason, pathologists sometimes include a note in the report, explaining that the diagnosis is based on the available tissue and that careful follow-up is recommended.

Questions to ask your doctor

If your pathology report shows a ganglioneuroma, you may find it helpful to ask your doctor the following questions:

• Where in my body was the tumor located?

• Was the tumor completely removed?

• Did the report describe a maturing or mature ganglioneuroma?

• Were any areas of neuroblastoma or ganglioneuroblastoma seen?

• Do I need any follow-up imaging or tests after surgery?

• Could this tumor cause symptoms in the future if it grows back?