Written By: Devin Golden

Biphasic Mesothelioma

Biphasic mesothelioma is a combination of epithelioid and sarcomatoid cells. This cell type is the second most common. A patient’s prognosis heavily depends on the ratio of epithelioid to sarcomatoid cells.


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Important Facts About Biphasic Mesothelioma

  • Biphasic mesothelioma has a mixture of two cell types: epithelioid and sarcomatoid.
  • The diagnosis is rare and treatment options vary on a case-by-case basis.
  • The average survival is 13 months for biphasic mesothelioma.

What Is Biphasic Mesothelioma?

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Biphasic Cell Type

Biphasic mesothelioma includes both epithelioid mesothelioma cells and sarcomatoid mesothelioma cells. Biphasic mesothelioma accounts for between 20% and 30% of cases.

For a mesothelioma diagnosis to qualify as biphasic, both cell types must account for at least 10% of the cells. If the minority cell type accounts for less than 10%, then the disease is diagnosed as the majority type.

Tumors with a higher epithelioid mesothelioma cell ratio typically grow faster but do not spread fast. Tumors with a higher sarcomatoid mesothelioma cell ratio spread faster.

Characteristics of Biphasic Cells

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Cell Description

A biphasic diagnosis involves a mixture of the other two mesothelioma cell types. This means the patient’s prognosis depends on which cell is more prevalent. More epithelioid cells for the patient equals a better prognosis.

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Cell Behavior

The behavior of a biphasic diagnosis is dependent on the ratio of cells. A mesothelioma with more sarcomatoid cells will spread quicker than a mesothelioma with more epithelioid cells.

Biphasic Mesothelioma Symptoms

Biphasic mesothelioma symptoms resemble those of epithelioid mesothelioma and sarcomatoid mesothelioma. Symptoms vary depending on if the disease is pleural or peritoneal.

Symptoms of biphasic pleural mesothelioma include:

  • Pain in the chest or lower back
  • Difficulty breathing and swallowing
  • Coughing
  • Pleural effusions (fluid buildup in the pleura)

Symptoms of biphasic peritoneal mesothelioma include:

  • Abdominal pain
  • Ascites (fluid in the abdomen)
  • Constipation
  • Nausea


Doctors use a technique called immunohistochemistry to diagnose mesothelioma. Once a biopsy is performed and tissue is removed, experts coat the cells with dye to make the proteins visible. These proteins are markers to detect if cancer is present.

Specialists are extremely important for diagnosing mesothelioma. Treatment can vary depending on the diagnosis, including cell type is most prominent.


Treatment for biphasic mesothelioma includes chemotherapy, radiation and surgery. New treatments, such as gene therapy and immunotherapy, also work for many biphasic mesothelioma cases.



For early-stage pleural mesothelioma, the main surgical options are extrapleural pneumonectomy and pleurectomy with decortication.

For early-stage peritoneal mesothelioma, the primary surgery is cytoreduction with heated intraperitoneal chemotherapy (HIPEC). Doctors will consider the ratio of cells when determining if surgery is an option.


Chemotherapy, Radiation and Emerging Methods

The newest pathology recommendations state that biphasic mesothelioma patients shouldn’t be excluded from receiving chemotherapy. The report also states these patients should be eligible for clinical trials, which could test emerging treatment methods.

Depending on where the cancer forms, biphasic mesothelioma patients may also receive radiation. This treatment is usually combined with surgery or chemotherapy.

Misdiagnosis of biphasic mesothelioma is common because the cancer is so rare. Get in touch with a specialist for a second opinion using our free Doctor Match program.


Patients with a biphasic mesothelioma largely comprised of epithelioid cells tend to have a better prognosis than those with mostly sarcomatoid cells.

A study published in the Annals of Surgical Oncology showed how cytoreduction and HIPEC is used for biphasic peritoneal mesothelioma. The median survival time was 6.8 years following complete resection.

Another report in the Annals of Surgical Oncology showed the survival times for biphasic pleural mesothelioma after surgery. The median overall survival for the 354 patients analyzed was 15.8 months.

A 2018 study in Clinical Lung Cancer shows the average survival time for each mesothelioma cell type:

  • Biphasic patients lived for an average of 9.5 months following their diagnosis.
  • Epithelioid patients survived for 14.5 months on average.
  • Undergoing surgery lengthened the average survival time by around six months for biphasic and epithelioid patients.

There have been cases of biphasic mesothelioma patients living longer than the average survival rate. Receiving mesothelioma treatment from a specialist is the most effective way to improve your prognosis.

Frequently Asked Questions About Biphasic Mesothelioma

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What does biphasic mesothelioma mean?

Biphasic mesothelioma is a combination of both epithelioid cells and sarcomatoid cells. For a case to constitute formally as biphasic mesothelioma, it must consist of at least 10% of both types of cells. The physical appearance of biphasic mesothelioma depends on the ratio of epithelioid cells to sarcomatoid cells.

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How common is biphasic mesothelioma?

Biphasic mesothelioma accounts for between 20% and 30% of all mesothelioma cases. It can occur in both pleural mesothelioma and peritoneal mesothelioma, although it’s more likely for the former.

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How long do people with biphasic mesothelioma live?

The average life expectancy for biphasic mesothelioma is 9-10 months following diagnosis. Surgery can extend a patient’s life by a few months, or even multiple years. The prognosis also depends on whether the cancer consists of more epithelioid cells or more sarcomatoid cells.

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How is biphasic mesothelioma treated?

Treatment for biphasic mesothelioma depends on which cell type makes up the majority of cells in the tumors. If the cancer is mostly epithelioid cells, then doctors may use surgery since they’ll be able to remove them easily. If the biphasic mesothelioma is made up mostly of sarcomatoid cells, then palliative treatments are offered.

Last Edited: June 1, 2023.

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