A doctor looking at an x-ray pictures of lungsBiphasic mesotheliod cells are one of three cell types that cause mesothelioma. It is a mixed tumor, which actually contains some of each of the other types of mestothelioid cells (epithelioid and sarcomatmoid). Biphasic mesothelioma is responsible for 20 to 35 percent of mesothelioma cases.

The mix of cells that a patient’s biphasic mesothelioma tumors contain may have a significant effect on the prognosis. Biphasic mesothelioma cases with a greater percentage of epithelioid cells tend to have a better prognosis.

Biphasic Mesothelioma

Mesothelioma is a rare cancer which is caused by asbestos exposure. The thin, needlelike fibers of asbestos may be inhaled or ingested where they lodge in the mesothelial lining of the lungs, abdomen, heart or testicles. Over a long period of time (20 to 50 years), the asbestos fibers cause inflammation and mutations in the cellular DNA which trigger the cells to begin dividing uncontrollably.

There are three main types of mesothelioma cells:

  • Epithelioid – epithelial cells are found in places like the skin and gastrointestinal tract, along with the mesothelium
  • Sarcomatoid – sarcoma cells originate from soft tissue, once they become cancerous they are known as sarcomatoid
  • Biphasic – a mix of the two types of cells, the percentage of the mix may have an impact on disease progression

Biphasic Mesothelioma Characteristics

Biphasic mesothelioma tumors are composed of a mix of the two different types of mesothelioid cells and may take on more of the characteristics of either type of cell. This commonly depends on which type is more prevalent but biphasic mesothelioma may be unpredictable as well.

When a larger percentage of mesothelioma cells are epithelioid, the tumor tends to be more organized and solid. Epithelial cells are uniform in nature and tend to “stick” together and even though they are cancerous, they tend to behave similarly. Though epithelioid cells divide more rapidly once cancerous and tumors may be larger, they do not tend to break away to metastasize as easily

When sarcomatoid cells represent a larger portion of a mesothelioma tumor, the tissue may be described as diffuse, disorganized or fibrous. Sarcomatoid tumors tend to form in nodules or sheets which makes surgical removal difficult. In addition, the tumors can form liquid centers and cells may break away easily, resulting in spreading of the cancer through the lymph system.

Biphasic mesothelioma which contains more sarcomatoid cells tends to be more difficult to treat than epithelioid-tending biphasic mesothelioma, which has a better prognosis.


Biphasic mesothelioma is the second most common cellular type of mesothelioma and accounts for about 20 to 35 percent of mesothelioma diagnoses. It may occur in any type of mesothelioma (pleural, peritoneal, pericardial and testicular). Biphasic cell types may also be found in other types of cancer including breast, colon and other cancers.


Biphasic mesothelioma can be difficult to diagnose. This is because within a tumor, each type of cell may be grouped together with areas of the tumor that are largely epithelioid and areas that are mostly sarcomatoid. Sarcomatoid cells are elongated with a large nucleus or possibly more than one nucleus. Epithelioid cells tend to be small, squarish cells with a clearly visible nucleus.

In order to diagnose biphasic mesothelioma, a biopsy will need to be taken. Small amounts of tissue may be taken from multiple locations in the tumor. These tissue samples will then be examined microscopically by a pathologist who will use a staining technique known as immunohistochemistry to identify both types of cells.


The behavior of the cancer will depend on the type of cells that are most prevalent. Epithelioid cells tend to grow, larger, solid tumors which do not spread as easily where sarcomatoid cells tend to form loose, disorganized tumors which may break apart or spread more easily. Because biphasic mesothelioma contains both types of cells within the same tumor, the behavior of the cancer may be unpredictable.

Biphasic Mesothelioma Diagnosis

After the confirmation of prior asbestos exposure and initial diagnosis of mesothelioma which will be performed through imaging studies, blood testing and biopsy. A pathologist will identify the cell type through microscopic magnification and staining.

Biphasic cell types make up 20 to 35 percent of all mesothelioma cases. They are also found in other types of cancer such as kidney, breast and colon cancers along with others. Biphasic mesothelioma cells may also be similar in appearance to another type of cancer cell, adenocarcinoma, other sarcoma-type cells, or may look similar to healthy tissue.

Because of the difficulty in diagnosing biphasic mesothelioma, patients who receive any diagnosis of mesothelioma should seek treatment from a specialist. A Mesothelioma specialist will have the expertise and experience in treating this rare disease, to ensure the best possible outcome.

Though diagnosis may be difficult and cancer behavior may be unpredictable, symptoms of biphasisc mesothelioma will depend largely on the location and type of mesothelioma.

Pleural biphasic mesothelioma may cause symptoms of:

  • Chest pain
  • Shortness of breath and difficulty breathing
  • Fluid collection in lungs
  • Weakness and fatigue
  • Difficulty swallowing
  • Weight loss

Peritoneal biphasic mesothelioma may cause symptoms of:

  • Abdominal pain
  • Ascites or abdominal fluid collection
  • Nausea
  • Loss of appetite or feeling of “fullness”


Mesothelioma treatment is largely based on where the disease is located and the stage of the cancer but the cell type, may determine how likely the treatment is to be successful.

Typical options for treatment involve:

Surgery to remove tumor. Biphasic mesothelioma that is more sarcomatoid in behavior may not be as responsive to surgical removal as sheeting of tumor and disease invasiveness make tumor removal more difficult. Epithelioid-type biphasic mesothelioma may be more responsive to surgery, depending on the stage of the cancer.

Radiation to reduce tumor size and eradicate tumor cells. The usefulness of radiation depends largely on the location and stage of mesothelioma. If the cancer has invaded or is threatening vital lung or cardiac tissue, radiation may not be an option. In other cases, radiation may prove successful, particularly if computer-assisted radiotherapy is used.

Traditional chemotherapy to kill cancer cells and shrink tumor size. Chemotherapy may be used alongside other treatments or as a standalone treatment and multiple combinations of medications may be used. Depending on the stage of the biphasic mesothelioma, it may be used as a curative measure to improve life-expectancy or it may be used as a palliative measure to reduce severe symptoms.

Newer treatment options such as targeted therapy or immunotherapy may be based on a patient’s particular DNA analysis which may show a greater likelihood of success. Clinical investigations are ongoing that may prove helpful with this unpredictable type of mesothelioma. Mesothelioma specialists will be able to ensure that all biphasic mesothelioma treatment options are examined and may know of additional investigational trials in progress.

Prognosis of Biphasic Mesothelioma

Biphasic mesothelioma prognosis is dependent upon whether more cells are epithelioid or sarcomatoid. Those with a larger percentage of epithelioid cells tend to have more treatment options, greater treatment success and a better prognosis. Some patients with sarcomatoid-type biphasic mesothelioma have shown that with early detection and appropriate treatment are significant factors in having a better prognosis.

Seeking a second opinion and advice from a mesothelioma specialist is vital for the patient with biphasic mesothelioma to avoid misdiagnosis or treatment delays which will worsen the prognosis. Treatment by a specialist will also offer comprehensive exploration of all treatment options and potentially provide better outcome for the biphasic mesothelioma patient.