Biphasic Mesothelioma

Biphasic mesothelioma contains varying amounts of epithelioid and sarcomatoid cells. Epithelioid-dominant biphasic mesothelioma typically has more treatment options, a better prognosis, and a greater life expectancy. Alternatively, biphasic tumors with more sarcomatoid cells may mean a more aggressive cancer.

Fact-Checked and Medically Reviewed By: Dr. Mark Levin

What Is Biphasic Mesothelioma?

Biphasic mesothelioma is a type of mesothelioma that is made up of two cell types. It is the second most common cell type for malignant mesothelioma.

The most common type of mesothelioma is epithelial mesothelioma. The least common type is sarcomatoid mesothelioma. In between is a mixture of the two types, called biphasic mesothelioma.

Did You Know?

The main difference between these two mesothelioma cell types is the shape of the cells under the microscope.

Biphasic mesothelioma cancers contain round cells characteristic of epithelial mesothelioma, which do spread as quickly throughout the body.

However, the biphasic cell type also has sarcomatoid cells, which look like long narrow spindles. Because of their shape, they do not stay together as well and tend to move more throughout the body, causing the biphasic malignant mesothelioma to spread more rapidly.

Biphasic mesothelioma treatment can vary depending on the stage of the mesothelioma, as well as the relative proportion of these cells. Patients with a higher percentage of epithelial cells than sarcomatoid cells respond better to treatment.

Quick Facts About Biphasic Mesothelioma
  • Biphasic mesothelioma is not a distinct cell type, but a mixture of epithelioid and sarcomatoid cell types.
  • According to the American Cancer Society (ACS), 20%-30% of mesothelioma cases are biphasic.
  • Roughly 20% of biphasic mesothelioma patients live at least 5 years after diagnosis.
  • The higher the ratio of epithelioid to sarcomatoid cells, the better a biphasic mesothelioma patient’s outlook is.

Biphasic Mesothelioma Symptoms

Biphasic mesothelioma has several symptoms that may present before a patient goes to the doctor. Symptoms do not differ dramatically from other types of mesothelioma.

They do differ based on where the biphasic mesothelioma is located within the body, however.

Patients with biphasic mesothelioma may experience:

  • Blood in stool (fecal matter)
  • Chest pain
  • Coughing up blood
  • Dry cough
  • Shortness of breath
  • Shoulder and rib pain
  • Swelling
  • Unexplained weight loss
  • Upper back pain
  • Vomiting up blood

While patients could have other symptoms, these are the main ones that doctors first hear about when a patient comes to them.

There is often fluid buildup in the lungs or abdomen, but this would only be seen on an initial X-ray. It can be identified on a physical exam. This fluid buildup can produce shortness of breath.

Biphasic Mesothelioma Diagnosis

Biphasic malignant mesothelioma is diagnosed through a variety of methods.

After a physical exam, doctors use imaging tests such as X-rays and computed tomography (CT) scans to look for signs of mesothelioma and locate the tumor.

Afterward, a biopsy is performed.

Did You Know?

While imaging scans can help a doctor make a mesothelioma diagnosis, a biopsy must be done to confirm the diagnosis.

Pathologists (doctors who specialize in examining diseased tissue and making diagnoses) examine the cells of a mesothelioma tissue sample taken from the patient.

They use techniques such as immunohistochemistry to find characteristics unique to certain cell types. For a biphasic mesothelioma diagnosis, both sarcomatoid and epithelial cells must be present.

Rare Types of Biphasic Mesothelioma Cells

Biphasic mesothelioma tumors are sometimes made up of either a rare subtype of epithelioid or sarcomatoid cells. These types occur in less than 1% of all mesothelioma cases.

Rare subtypes of biphasic mesothelioma include: 

  • Adenoid cystic mesothelioma: This is an extremely rare type of epithelial mesothelioma. Since 2013, only 153 cases have been reported worldwide.
  • Adenomatoid mesothelioma: A common secondary arrangement of epithelial malignant mesothelioma. It can also be called glandular or microglandular mesothelioma.
  • Deciduoid Mesothelioma: This is an uncommon type of epithelial mesothelioma that forms in the lining of the abdomen. It is most commonly found in young women, shortly after pregnancy.
  • Papillary Mesothelioma: This is often called well-differentiated papillary mesothelioma. It is very uncommon and is formed in the peritoneum (lining of the abdomen).
  • Small Cell Mesothelioma: This is an extremely uncommon type of mesothelioma. It is named because of its very small cell size.
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Biphasic Mesothelioma Prognosis

The general prognosis (disease outlook) of biphasic mesothelioma depends largely on the percentage of epithelial versus sarcomatoid cells. If the mesothelioma has more epithelial cells, the prognosis is better than if the sarcomatoid proportion is higher.

Epithelial cells are easier to target because they do not spread throughout the body in the same way sarcomatoid cells do.

Studies show that the general life expectancy for biphasic malignant mesothelioma is about 1 year. Most research shows that it falls between 6 months and 5 years.

Biphasic Mesothelioma Survival Rate

Survival rates for biphasic mesothelioma are about 20% after 5 years.

This means that around 20% of patients with biphasic mesothelioma live at least 5 years after diagnosis.

Biphasic Mesothelioma Treatment

There are several different mesothelioma treatment options for patients who are diagnosed with biphasic mesothelioma. A doctor will present a patient with the one that best fits his or her stage and type of biphasic mesothelioma.

A lot depends on the patient’s age, mesothelioma stage, and percentage of sarcomatoid versus epithelial cells.


Chemotherapy is often the first treatment used for biphasic mesothelioma. It may work well for patients with a large number of epithelioid mesothelioma cells, especially when combined with surgery.

Sarcomatoid-dominant biphasic mesothelioma is more resistant to treatment, but chemotherapy may still help because it gets around the entire body, destroying sarcomatoid cells that had spread.

Chemotherapy may be more or less effective depending on the age, health, and cancer stage of the patient, as well as how well an individual patient tolerates chemotherapy.

Radiation Therapy

Radiation therapy is mainly used to reduce the pain and suffering of a patient. It may be difficult to focus and precisely but safely target the mesothelioma.


Mesothelioma surgery is often an aggressive treatment option, but it can be effective if the biphasic mesothelioma is primarily made up of epithelioid cells.

These cells hold together well and do not usually spread as quickly throughout the body, so surgeons can often remove all visible cancer, improving survival.

If the patient’s biphasic mesothelioma consists of more sarcomatoid cells, a doctor may not suggest mesothelioma surgery because the cancer can travel throughout the body, growing in more places than surgeons can safely remove with surgery.

Other Treatment

Clinical trials are ongoing studies of new drugs or treatments that may cure or improve a disease. Patients often have to meet certain criteria to participate in a clinical trial.

Immunotherapy is a treatment that doctors are using more and more frequently for mesothelioma patients. This treatment assists a patient’s own immune system to fight the cancer.

Genetic testing is also being used to determine who might be more predisposed to getting mesothelioma, helping people in these groups get diagnosed earlier and improving their prognosis.

Photodynamic therapy is an emerging science that uses light to kill cancer.

Because mesothelioma specialists are always testing new and emerging clinical trials, it is best to inform your doctor or medical team that you are open to participating in a clinical trial. They can find the one that best fits your condition and circumstances.

To learn whether you may be eligible to receive money to help pay for treatment, get a free case review.

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Hope for Victims of Biphasic Mesothelioma

Patients with biphasic mesothelioma have access to new treatments in clinical trials. As traditional treatments become more effective and knowledge of the disease grows, patient care and life expectancy are only expected to improve.

The Mesothelioma Hope team is here to support you as you navigate your diagnosis.

Whether you or your loved one needs help finding a doctor, information on treatment options, or exploring treatment payment options, we can help.

Get our free mesothelioma guide today.

Reviewed by:Dr. Mark Levin

Certified Oncologist and Hematologist

  • Fact-Checked
  • Editor

Mark Levin, MD has over 30 years of experience in academic and community hematology and oncology. In addition to serving as Chief or Director at four different teaching institutions throughout his life, he is also still a practicing clinician, has taught and designed formal education programs, and has authored numerous publications in various fields related to hematology and oncology.

Dr. Mark Levin is an independently paid medical reviewer.

  • Board Certified Oncologist
  • 30+ Years Experience
  • Published Medical Author

Mesothelioma Hope was founded by a team of passionate health advocates to educate people about this aggressive form of cancer. Mesothelioma affects thousands of people each year. Our team works tirelessly to give hope to those impacted by mesothelioma. Learn more about operating principles and our Editorial Guidelines.

9 References
  1. Patricia M. Baker, American Journal of Clinical Pathology, “Malignant Peritoneal Mesothelioma in Women: A Study of 75 Cases With Emphasis on Their Morphologic Spectrum and Differential Diagnosis.” Accessed on February 19, 2018.

  2. American Cancer Society, “About Malignant Mesotheiloma” Retrieved from: Accessed on February 19, 2018.

  3. Case Reports in Pulmonology, “Biphasic Malignant Pleural Mesothelioma Masquerading as a Primary Skeletal Tumor.” Retrieved from: Accessed on February 19, 2018.

  4. Archives of Pathology and Laboratory Medicine, “Guidelines for Pathologic Diagnosis of Malignant Mesothelioma: A Consensus Statement from the International Mesothelioma Interest Group” Retrieved from: Accessed on February 19, 2018.

  5. Inai K. (2008). Pathology of mesothelioma. Environmental health and preventive medicine, 13(2), 60–64. Retrieved April 15, 2020, from

  6. The American Cancer Society medical and editorial content team. (2018). What Is Malignant Mesothelioma? Retrieved April 15, 2020, from

  7. History of Oncolytic Viruses: Genesis to Genetic Engineering. Molecular Therapy. Retrieved from: Accessed: 03/30/20.

  8. Cancer Immunotherapy. American Cancer Society. Retrieved from: Accessed: 03/30/20.

  9. Photodynamic Therapy. American Cancer Society. Retrieved from: Accessed: 03/30/20.

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