Diagnosis of Peritoneal Mesothelioma

How Doctors Identify This Rare and Often Overlooked Cancer

Peritoneal mesothelioma is a rare cancer affecting the lining of the abdominal cavity. It’s almost always caused by asbestos exposure—but its symptoms are often vague or misdiagnosed. That makes early, accurate diagnosis essential.

This page explains how peritoneal mesothelioma is diagnosed, which tests are involved, and why catching it early can significantly improve treatment outcomes.

Why Peritoneal Mesothelioma Is Hard to Diagnose

Peritoneal mesothelioma is often mistaken for:

  • Ovarian cancer (in women)

  • IBS or Crohn’s disease

  • Hernias or bowel disorders

  • Gallbladder or liver disease

Because symptoms like bloating, indigestion, or abdominal pain are so common, doctors may not initially suspect cancer—especially if a patient doesn’t mention past asbestos exposure.

Tip: If you have any history of asbestos exposure, share that information early and clearly with your doctor.

The Diagnostic Process

Diagnosing peritoneal mesothelioma typically involves multiple steps, starting with symptom review and moving toward imaging, fluid tests, and ultimately a biopsy.

🔍 1. Medical History & Exposure Review

Doctors will begin by:

  • Asking about symptoms like abdominal pain, swelling, or weight loss

  • Reviewing any past asbestos exposure (occupational or secondhand)

Your asbestos exposure history is one of the most important clues in reaching the correct diagnosis.

🖼 2. Imaging Tests

These scans help locate tumors, check for fluid buildup, and assess how far the disease has spread.

  • X-Ray: Can reveal fluid (ascites) or abnormal masses

  • CT Scan: Gives a detailed view of the abdominal cavity

  • PET Scan: Highlights cancer activity throughout the body

Imaging alone can’t confirm mesothelioma, but it helps narrow down the possible causes.

💉 3. Blood Tests & Biomarkers

Doctors may run blood tests to check for substances associated with mesothelioma, such as:

  • Mesothelin

  • Fibulin-3

  • CA-125 (commonly used in women)

While not definitive, these markers can support the case for further testing.

🧪 4. Biopsy: The Only Way to Confirm Diagnosis

A biopsy is required to officially confirm peritoneal mesothelioma. It involves removing a small sample of tissue or fluid and analyzing it under a microscope.

Common Biopsy Types:

  • Needle biopsy: A thin needle is used to collect tissue, often guided by CT

  • Laparoscopy: A small camera is inserted into the abdomen to visually examine organs and take precise samples

  • Fluid aspiration (paracentesis): May be used to test ascitic fluid but is not always conclusive

A pathologist will determine if mesothelioma is present and, if so, which cell type (epithelioid, sarcomatoid, or biphasic).

Challenges in Diagnosing Peritoneal Mesothelioma

  • Rare disease: Many doctors have never encountered a case

  • Non-specific symptoms: Bloating, fatigue, and bowel changes are easy to misattribute

  • Delayed suspicion: Without a known history of asbestos exposure, mesothelioma may not even be considered initially

That’s why it’s so important to push for further testing if symptoms persist and no clear cause is found.

Early Diagnosis Leads to Better Outcomes

If caught early—especially before widespread abdominal involvement—patients may be eligible for:

  • Cytoreductive surgery

  • HIPEC (heated intraperitoneal chemotherapy)

  • Longer survival and improved quality of life

Learn more about Treatment Options for Peritoneal Mesothelioma →

We Can Help You Get Diagnosed

Our legal-medical team helps people with suspected peritoneal mesothelioma:

  • Understand their risk

  • Get referred for the right tests

  • Connect with mesothelioma specialists

📞 Call 833-4-ASBESTOS
Or schedule your free health screening today.

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