What Is a Meningioma? Understanding the Brain Tumor Linked to Depo-Provera

A meningioma is a tumor that develops in the meninges — the three layers of protective tissue that surround the brain and spinal cord. Meningiomas are the most common type of primary brain tumor, accounting for approximately 40% of all brain tumors diagnosed in the United States. While they are typically classified as benign (non-cancerous), this classification can be misleading: meningiomas can grow large enough to compress brain tissue, causing serious neurological symptoms that dramatically impact quality of life.

For women who used Depo-Provera contraceptive injections, understanding meningiomas is critical. A growing body of scientific research — now acknowledged by the FDA’s December 2025 label update — has established a link between long-term use of depot medroxyprogesterone acetate (DMPA) and an increased risk of developing these brain tumors.

Types of Meningioma

Meningiomas are classified by the World Health Organization (WHO) into three grades based on their cellular characteristics and behavior:

Grade I (Benign)

Approximately 80% of meningiomas are Grade I. These tumors grow slowly and have well-defined borders. While the term “benign” suggests harmlessness, Grade I meningiomas can still cause significant symptoms depending on their size and location. Many require surgical removal or radiation therapy, and they can recur after treatment.

Grade II (Atypical)

Atypical meningiomas account for roughly 15-20% of cases. They grow more quickly than Grade I tumors and have a higher rate of recurrence after surgery. Treatment typically involves surgical removal followed by radiation therapy to reduce the risk of return.

Grade III (Malignant/Anaplastic)

The rarest and most aggressive form, Grade III meningiomas account for approximately 1-3% of cases. These tumors grow rapidly, are more likely to invade surrounding brain tissue, and have the highest recurrence rates. Treatment often requires aggressive surgery, radiation, and potentially chemotherapy.

Symptoms of Meningioma

Meningioma symptoms depend primarily on the tumor’s location and size. Because meningiomas typically grow slowly, symptoms may develop gradually over months or even years, which can delay diagnosis. Common symptoms include:

• Headaches — often the first symptom noticed, particularly headaches that worsen over time or are most severe in the morning
• Vision problems — blurred vision, double vision, or partial vision loss, especially when the tumor is near the optic nerve
• Hearing loss or tinnitus — ringing in the ears or progressive hearing loss when the tumor affects the temporal bone area
• Seizures — new-onset seizures in an adult are always a red flag that warrants brain imaging
• Cognitive changes — memory problems, difficulty concentrating, personality changes, or confusion
• Weakness or numbness — in the arms, legs, or face, depending on which area of the brain is compressed
• Balance and coordination problems — difficulty walking, dizziness, or loss of fine motor skills
• Speech difficulties — trouble finding words or slurred speech

Many women who developed meningiomas after using Depo-Provera report that their symptoms were initially attributed to other causes — migraines, stress, aging — before imaging revealed the tumor. This delay in diagnosis is a common pattern in the cases we review.

How Meningiomas Are Diagnosed

Imaging Studies

The primary diagnostic tools for meningioma are brain imaging studies:

• MRI (Magnetic Resonance Imaging) — the gold standard for detecting and characterizing meningiomas. MRI provides detailed images of soft tissue and can identify the tumor’s exact location, size, and relationship to surrounding brain structures. Contrast-enhanced MRI (with gadolinium) is particularly useful for meningioma detection.

• CT Scan (Computed Tomography) — often the first imaging study performed, particularly in emergency settings. CT scans can detect meningiomas and are especially good at showing calcification within the tumor and any effect on nearby bone.

Confirming the Diagnosis

While imaging can strongly suggest a meningioma based on its characteristic appearance, definitive diagnosis requires examination of the tumor tissue:

• Biopsy or surgical pathology — when a meningioma is surgically removed, the tissue is examined by a neuropathologist to confirm the diagnosis and determine the WHO grade
• In some cases, imaging characteristics are sufficiently distinctive that treatment decisions are made without a biopsy, particularly when surgery is not immediately indicated

Treatment Options

Treatment for meningioma depends on the tumor’s size, location, grade, and the patient’s overall health and symptoms.

Observation (Watch and Wait)

Small, asymptomatic meningiomas may be monitored with periodic MRI scans rather than treated immediately. This approach is common for incidentally discovered tumors in older patients. However, observation still requires ongoing medical surveillance and the psychological burden of living with a known brain tumor.

Surgery

Surgical removal (resection) is the primary treatment for symptomatic meningiomas. The procedure, called a craniotomy, involves opening a section of the skull to access and remove the tumor. Key considerations include:

• Complete vs. partial removal — the goal is total removal, but the tumor’s location may make complete resection impossible without risking damage to critical brain structures
• Recovery — brain surgery carries inherent risks including infection, bleeding, neurological deficits, and a recovery period that can extend weeks to months
• Recurrence — even after complete removal, meningiomas can recur, particularly Grade II and III tumors

Radiation Therapy

Radiation may be used alone or after surgery:

• Stereotactic radiosurgery (Gamma Knife, CyberKnife) — delivers focused radiation to the tumor with minimal impact on surrounding tissue, typically used for smaller tumors or tumors in locations difficult to reach surgically
• Fractionated radiation therapy — delivers radiation in smaller doses over multiple sessions, used for larger tumors or as a follow-up to partial surgical removal

The Depo-Provera Connection

The link between Depo-Provera and meningioma is rooted in biology. Meningiomas frequently express progesterone receptors — in fact, approximately two-thirds of meningiomas test positive for progesterone receptors. This means that progesterone and synthetic progestins can directly stimulate the growth of these tumors.

Depo-Provera’s active ingredient, depot medroxyprogesterone acetate (DMPA), is a high-dose synthetic progestin. The landmark BMJ study found that prolonged use of injectable progestins like DMPA was associated with a substantially elevated risk of intracranial meningioma. The risk increased with longer duration of use, establishing a dose-response relationship that strengthens the causal connection.

The FDA’s acknowledgment of this risk in its December 2025 label update was a watershed moment. For decades, Pfizer’s labeling for Depo-Provera did not warn about the meningioma risk, despite the growing body of evidence. The litigation alleges that Pfizer knew or should have known about this risk and failed to protect patients.

For more on the litigation timeline and FDA actions, see our timeline of FDA warnings and studies.

Frequently Asked Questions

Are all meningiomas caused by Depo-Provera?

No. Meningiomas can occur without any known cause. However, the research shows that Depo-Provera significantly increases the risk. If you used Depo-Provera and were diagnosed with a meningioma, the connection warrants investigation.

Can a meningioma go away on its own?

In very rare cases, small meningiomas may stop growing or even shrink slightly, particularly after removal of hormonal stimulation (such as discontinuing Depo-Provera). However, most meningiomas do not resolve on their own and require monitoring, treatment, or both.

How soon after Depo-Provera use can a meningioma develop?

The timeline varies. Some women have been diagnosed years or even decades after their last injection. Because meningiomas grow slowly, a tumor stimulated by years of progestin exposure may not become symptomatic until well after the drug was discontinued.

Should I get screened for meningioma if I used Depo-Provera?

If you used Depo-Provera for an extended period and are experiencing any neurological symptoms — persistent headaches, vision changes, seizures, cognitive difficulties — discuss brain imaging with your doctor. Even without symptoms, some women choose to undergo screening given the established risk.

What if I was diagnosed with a meningioma but never told about the Depo-Provera connection?

This is a common situation, particularly for women diagnosed before the FDA’s 2025 label update. Many healthcare providers were not aware of the link. If you have a meningioma diagnosis and a history of Depo-Provera use, a legal evaluation can help determine whether you have a viable claim.

Take the Next Step

If you or a loved one used Depo-Provera and have been diagnosed with a meningioma — or are experiencing symptoms that could indicate a brain tumor — understanding your medical and legal options is critical. Early action preserves your rights and ensures you receive appropriate medical care.

If you’ve been affected, request a free case review today.

Advertisement. This content is provided for informational purposes only and does not constitute legal advice. NuLegal | Ashkaan Hassan, Esq. | CA Bar #283629