Written By: Devin Golden

Mesothelioma Peritoneal Fluid Analysis

Mesothelioma peritoneal fluid analysis is another way of saying a peritoneal mesothelioma fluid biopsy test, or peritoneal cytology. This is a lab test doctors may use when determining a peritoneal mesothelioma diagnosis. A peritoneal fluid analysis can help them learn if there are peritoneal mesothelioma cancer cells in a patient’s body.

Karen Ritter, RN BSN

Medically Reviewed By

Karen Ritter, RN BSN

Registered Nurse

Karen Ritter, RN BSN

Medically Reviewed By

Karen Ritter, RN BSN

Registered Nurse


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What Is Peritoneal Fluid?

Peritoneal fluid is found between the layers of the peritoneum, also called the peritoneal space. The peritoneum is made up of two layers of tissue – the visceral peritoneum and the parietal peritoneum – with fluid in between. The peritoneum is a thin lining surrounding the abdominal cavity and all of its organs.

Cancer that forms in the peritoneum is called peritoneal mesotheliom (the cancer comes from mutated mesothelial cells). The only cause of peritoneal mesothelioma is exposure to asbestos, which is a naturally occurring mineral. This mineral can break apart into loose, sharp fibers. When the fibers are inhaled or swallowed, they can move through the digestive tract and eventually reach the peritoneum.

How Is a Peritoneal Fluid Analysis Performed?

The peritoneum includes two tissue linings made up of mesothelial cells. Therefore, peritoneal fluid can contain mesothelial cells. If this fluid is cancerous, then doctors can remove samples of the fluid to find evidence of peritoneal mesothelioma. Collecting this fluid is how doctors perform a peritoneal fluid analysis.

There are specific biomarkers – such as proteins – expressed by peritoneal mesothelioma cancer. If you have this cancer, then the proteins may show up in the peritoneal fluid.

What Is Ascites?

Ascites is a fluid buildup in the peritoneum. This fluid collects in between the two tissue layers of the peritoneum, called the peritoneal space.

When this is a symptom of peritoneal mesothelioma, the fluid buildup is caused by tumors in the peritoneal space. Ascites occur due to irritation and scar tissue developing in the peritoneum from asbestos fibers. This scar tissue leads to a disruption in the normal transfer of fluid across the mesothelial cells of the peritoneum, which forms pockets of fluid.

Since ascites is an accumulation of excess fluid, doctors will drain the fluid to ease the patient’s discomfort, the collected fluid samples are then sent for testing.

Mesothelioma Peritoneal Fluid Analysis for Diagnosing Peritoneal Mesothelioma

Analyzing peritoneal fluid can help give a peritoneal mesothelioma diagnosis. However, a fluid analysis is less definitive than a tissue analysis for diagnosing mesothelioma. This fact is why many doctors prefer to perform a tissue biopsy for diagnostic purposes.

Paracentesis for a Peritoneal Fluid Analysis

The main medical approach to getting fluid samples for a mesothelioma peritoneal fluid analysis is called a paracentesis. This is a minimally invasive peritoneal mesothelioma procedure that requires a needle and syringe.

The medical team will numb a small area of your abdomen. A needle is inserted through the skin to retrieve a fluid sample and collect it in a syringe. An ultrasound is often used to guide the doctor to the peritoneal fluid. The fluid sample is collected and sent to a lab for the mesothelioma peritoneal fluid analysis.

Frequently Asked Questions About Mesothelioma Peritoneal Fluid Analysis

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Are Mesothelial Cells Normal in Peritoneal Fluid?

Yes, mesothelial cells are normal in peritoneal fluid. The peritoneum is made up of two tissue linings composed of mesothelial cells with fluid in between. It’s common for mesothelial cells to exist within peritoneal fluid.

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How Is a Peritoneal Fluid Analysis Performed?

A peritoneal fluid analysis is performed in a laboratory. Doctors test for specific proteins for the presence of peritoneal mesothelioma or another cancer. The medical team collects the fluid through a procedure called a paracentesis. This procedure involves using a needle and syringe to retrieve samples of fluid from the peritoneum. This fluid is called ascites, which is a buildup of fluid in the peritoneal space. Ascites can be a symptom of peritoneal mesothelioma.

Sources & Author

  1. Guidelines for cytopathologic diagnosis of epithelioid and mixed type malignant mesothelioma. Complementary statement from the International Mesothelioma Interest Group, also endorsed by the International Academy of Cytology and the Papanicolaou Society of Cytopathology. CytoJournal. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4678521/. Accessed: 03/24/2023.
  2. Peritoneal fluid analysis. MedlinePlus. Retrieved from: https://medlineplus.gov/ency/article/003626.htm. Accessed: 03/24/2023.
Devin Golden

About the Writer, Devin Golden

Devin Golden is a content writer for Mesothelioma Guide. He produces mesothelioma-related content on various mediums, including the Mesothelioma Guide website and social media channels. Devin's objective is to translate complex information regarding mesothelioma into informative, easily absorbable content to help patients and their loved ones.