Who should be tested for mesothelioma?

People with a history of asbestos exposure and symptoms such as chest pain or shortness of breath should ask their doctor about testing for mesothelioma. They may recommend imaging scans, blood tests and a biopsy to diagnose mesothelioma.

How long does it take to get a mesothelioma diagnosis?

About 3 months is the average time it takes to get a mesothelioma diagnosis. This is after the first symptoms appear. The most common symptoms include shortness of breath and chest pain.

How do you prepare for a mesothelioma biopsy?

The first step in preparing for a mesothelioma biopsy is to stop all blood-thinning meds at least 5 days before your biopsy. Don’t eat or drink anything 6 hours before your appointment. Wear loose clothes to the appointment. Also, arrange for a designated driver to take you home. Plan to spend several hours undergoing the biopsy. Some biopsies need at least one night in the hospital.

What test confirms mesothelioma?

Only a biopsy can confirm mesothelioma. A doctor removes a small piece of tissue from the tumor and sends it to a pathologist, who examines it under a microscope and identifies the cell type. Imaging scans, blood tests and fluid analysis can suggest mesothelioma but can't confirm it on their own. Doctors often recommend a second pathology opinion from a specialist before starting treatment.

Can mesothelioma be misdiagnosed?

Yes, mesothelioma is often misdiagnosed because its early symptoms like cough, chest pain and shortness of breath look like more common conditions such as pneumonia, COPD, lung cancer or heart problems. The average person waits about 3 months for an accurate diagnosis and many see several doctors first. A history of asbestos exposure and a tissue biopsy reviewed by a specialist pathologist are the best ways to avoid misdiagnosis.

Mesothelioma Diagnosis

Doctors diagnose mesothelioma using a combination of imaging scans, blood tests and fluid analysis, but only a biopsy can confirm it. Testing early and working with a mesothelioma specialist improves accuracy and opens more treatment options.

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Quick Answers

Four Questions About Your Mesothelioma Diagnosis

What's the first test?

Your primary doctor orders chest X-rays, CT scans or both after symptoms like shortness of breath or chest pain appear.

Should I see a specialist?

Yes. Because mesothelioma is rare, a specialist is best suited to read your scans and pathology reports, lessening a misdiagnosis.

What happens after diagnosis?

Your specialist stages the cancer and builds a treatment plan. Patient Advocates can help with doctors, treatment costs and support.

Could this condition be something else?

Yes. But people with past asbestos exposure and these early symptoms are at higher risk of mesothelioma.

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By the Numbers

~3 months

Average time from first symptoms to diagnosis
20 to 50 years

Latency period between asbestos exposure and symptoms
71%

Percentage of cases diagnosed after stage 1
48%

Percentage of patients diagnosed at stage 4

Expert Insights

How Doctors Test for Mesothelioma

The process of diagnosing mesothelioma starts with imaging tests and ends with a biopsy.

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The first test for a patient with, symptoms related to mesothelioma will be going to their primary doctor, getting an x-ray or a CAT scan done. Based on the results from that, they may go through further testing such as a thoracentesis or paracentesis, which is where they drain fluid, whether it’s from the lining of the lungs or the peritoneal area, which is the abdominal area. The next step would be for a biopsy.

The biopsy is a step where they confirm the diagnosis. This sample is sent to a pathologist who ultimately tests the sample taken out from the tumor and identifies it as mesothelioma.

Diagnostic Process
The Four Types
Misdiagnosis
Staging & Cell Types
Treatment Options
Early Detection
How We Help
FAQs

Understanding the Diagnosis

How Doctors Diagnose Mesothelioma

Diagnosis begins with a physical exam once symptoms appear. People with a known history of asbestos exposure may be screened earlier. Some cases are diagnosed incidentally during tests for unrelated conditions. However mesothelioma is diagnosed, doctors use a combination of a medical history, physical exam, imaging scans and biopsies to confirm this rare asbestos cancer.

Once mesothelioma is suspected, you’ll typically be referred to an oncologist who uses imaging to locate tumors and checks for signs of fluid buildup. Getting the right specialists involved early matters because the disease resembles other less serious conditions.

In Summary

Scans and symptoms can raise suspicion, but they can’t confirm mesothelioma. Only a biopsy, which involves removing a small tissue sample and examining it under a microscope, can confirm the disease and identify its cell type.

The Process of Diagnosing Mesothelioma

Physical Exam

During a physical exam your doctor may ask about your medical history, symptoms and asbestos exposure.

Imaging Tests

Imaging tests are used to identify the size and location of mesothelioma tumors and can include X-rays, CT scans, MRIs and PET-CT scans.

Blood Tests

While some blood tests can detect signs of mesothelioma, doctors use them primarily to rule out other diseases and to track treatment response.

Biopsy

Tissue samples taken during a biopsy allow doctors to determine the cancer cell type and stage, which helps them decide on a course of treatment.

Second Opinion

Mesothelioma symptoms are similar to many other diseases affecting the lungs, heart and abdominal organs, making misdiagnosis common.

“Just because your doctor told you that you have fluid around the lung does not necessarily mean you have mesothelioma. Even if you have asbestos exposure, you need to look further into it. Very often, you need a surgical biopsy or a core biopsy to make sure that you indeed have mesothelioma.”

— Dr. Jacques Fontaine, Thoracic Surgeon and Pleural Specialist

Type & Location

Four Types of Mesothelioma and How Each Is Diagnosed

Doctors use different tests to determine which type of mesothelioma they suspect. These tests will pull biopsies from the areas of the body the specific type of mesothelioma develops.

“The type of mesothelioma a patient has plays a critical role in determining the best approach,” said Dr. Catherine Perrault, chief medical officer and board-certified family physician with The Mesothelioma Center’s Medical Outreach Team. “Treatment options can vary significantly based on tumor type and characteristics, which is why patients need to understand how their medical team tailors recommendations to their specific diagnosis rather than applying a one-size-fits-all approach.”

Pleural

Lining of the lungs

~80-85% of diagnoses

Confirmed with thoracentesis and a thoracoscopy biopsy.

Peritoneal

Lining of the abdomen

~15-20% of diagnoses

Diagnosed via paracentesis and laparoscopy.

Pericardial

Lining of the heart

< 1% of diagnoses

Fluid drawn by pericardiocentesis.

Testicular

Lining of the testes

< 1% of diagnoses

Found during a physical exam of the groin and biopsy.

Learn more about the types of mesothelioma

Why It’s Often Missed

Why Is Mesothelioma Misdiagnosed?

Mesothelioma symptoms resemble everyday illnesses, and because the latency period can span decades, an asbestos-related cancer rarely comes to mind first. It’s important to be correctly diagnosed to avoid wasting time and money on treatments for the incorrect disease.

“Making an accurate mesothelioma diagnosis can be tough. The initial signs on imaging can be nonspecific and misdiagnosis can occur. It’s important to tell mesothelioma apart from other cancers, because the treatments are very different.”

- Dr. Catherine Perrault, Chief Medical Officer and Board-Certified Family Physician, The Mesothelioma Center Medical Outreach Team

Symptom	Often Mistaken For
Shortness of breath	Pneumonia, COPD
Chest or back pain	Heart problems, muscle strain
Persistent cough	Bronchitis
Fatigue & weight loss	Aging, other illnesses
Fluid buildup (effusion)	Infection, heart failure

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The Diagnostic Process

What the Path to a Mesothelioma Diagnosis Looks Like

The path to a mesothelioma diagnosis isn’t the same for everyone. Different symptoms lead doctors to different tests. Results of one test may lead to additional tests, and sometimes, other doctors perform those tests. But typically, a diagnosis may take 90 days before a mesothelioma specialist’s final confirmation.

Timeline of the Diagnostic Process for Mesothelioma

Day 1

Initial symptoms appear.
Day 2

X-rays identify fluid buildup.
Day 3 - Day 13

Antibiotic prescribed to treat pneumonia or fluid drained.
Day 14

Doctor orders follow-up X-rays, asks patient to return in 30 days.
Day 44

Follow-up X-rays show fluid buildup again. Doctor either drains fluid, orders PET scans and CT scans.
Day 54

Imaging scans show a possible underlying cause. Patient referred to surgeon or pulmonologist, which can take up to 15 days.
Day 69

Surgeon, pulmonologist or both schedule a biopsy appointment, which can take up to 10 days.
Day 79

Surgeon, pulmonologist or both take biopsy, which typically requires a hospital stay of 1-2 days. The biopsy results, also known as pathology, can take up to 10 days.
Day 89

(Approximately three months later): Mesothelioma is confirmed if biopsy tests positive for the disease.

"The day I found out I was diagnosed with mesothelioma, I was pretty scared. I was shocked. I was in shock. I felt like I was in the Twilight Zone. When they told me I was diagnosed with mesothelioma, no one knew what it was. I didn’t know what it was. My mom, my husband, no one. It was the day my whole life changed."

- Tamron Little, Peritoneal Mesothelioma Survivor

Staging & Cell Type

Mesothelioma Staging and Cell Type

Once a biopsy confirms mesothelioma, two findings shape everything that follows: the cancer’s cell type and how far it has spread, which leads to the mesothelioma stage. Together, they tell your care team how the disease is likely to behave and which treatments give you the best chance of survival.

Start with the pathology report

It documents the tumor’s exact cell type from your biopsy sample.

Identify the cell type

Epithelioid (50% to 70%, best prognosis), sarcomatoid (10% to 20%, most aggressive) or biphasic (20% to 35%, a mix).

Image the cancer spread

Scans map how far tumors have reached.

Apply TNM staging

Tumor, node, metastasis system.

Determine the stage

Stages 1 and 2 are early; stages 3 and 4 are advanced. A higher number means more spread.

Get a second opinion

A specialist pathology review reduces the risk of misdiagnosing mesothelioma before treatment begins.

“It’s important to not only know that it’s mesothelioma, It’s important to know the histological subtype. Is it epithelial, or is it sarcomatoid, or is it a mixture of both called mixed or biphasic? Knowing more about the tumor will allow us to find the right treatment for that tumor.”

- Dr. Jacques Fontaine, Thoracic Surgeon and Pleural Specialist

What Comes Next

Treatment Options After a Mesothelioma Diagnosis

A confirmed diagnosis and cell type let your specialist build a mesothelioma treatment plan. Common options include:

Surgery

Removes visible tumors; most effective in early-stage disease.

Chemotherapy

Systemic drugs that shrink tumors and slow spread.

Immunotherapy

Helps the immune system recognize and attack cancer cells.

Radiation

Targets tumors to control growth and relieve symptoms.

Multimodal therapy

Combines surgery, systemic therapy, radiation or all three.

Clinical trials

Access to emerging therapies not yet widely available.

Danielle DiPietro
Financial Advocate & Board Certified Patient Advocate

Worried About the Cost of Care?

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Why Timing Matters

An Early Mesothelioma Diagnosis Changes Your Options

Finding mesothelioma early lets doctors start treatment sooner and opens more options for improving survival and quality of life. But early detection remains rare.

The Mesothelioma Center’s 2025 Patient Survey of more than 200 survivors, caregivers and their loved ones found 48% of mesothelioma patients were diagnosed at stage 4. Fatigue was the most commonly reported symptom among people with pleural and peritoneal mesothelioma.

What Improves an Accurate Diagnosis

Sharing a history of asbestos exposure early, plus getting a specialist’s second opinion, are the biggest factors that lead to an earlier, more accurate diagnosis.

Stage at Diagnosis

Stage 1: 12% of Patients
Stage 2: 17% of Patients
Stage 3: 23% of Patients
Stage 4: 48% of Patients

Source: The Mesothelioma Center’s 2025 Survivor & Caregiver Survey

Real Diagnoses

Mesothelioma Diagnosis Stories From Real Survivors

Pleural mesothelioma

“…After three days, they told me the diagnosis was mesothelioma. We didn’t know what mesothelioma was.”

Michael Cole, pleural survivor

Peritoneal mesothelioma

“The day I found out I was diagnosed, I was in shock… It was the day my whole life changed.”

Tamron Little, peritoneal survivor

Early Detection

“After my surgery, I was told my mesothelioma was stage 1-B.” Caught after four bouts of pleurisy.

Kevin H., pleural survivor

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How Asbestos.com Helps

Guidance From People Who Do This Every Day

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FAQs

Common Questions About Diagnosing Mesothelioma

People with a history of asbestos exposure and symptoms like chest pain or shortness of breath. Doctors may recommend imaging scans, blood tests and a biopsy.

Only a biopsy. A pathologist examines tumor tissue under a microscope and identifies the cell type. A second pathology opinion from a specialist is often recommended before treatment.

Stop blood-thinning medications about five days ahead, avoid food and drink for six hours before, wear loose clothing and arrange a ride home. Some biopsies require an overnight hospital stay.

Yes. Its early symptoms mimic more common illnesses, so many patients see several doctors first. Sharing a history of asbestos exposure and having a biopsy reviewed by a specialist pathologist is the best safeguard.