According to 100 Questions & Answers About Mesothelioma, there are three main types of mesothelioma: epithelioid mesothelioma, sarcomatoid mesothelioma, and mixed (also called “biphasic”) mesothelioma.

Generally, when I speak with someone who has recently been diagnosed with mesothelioma, I ask the diagnosis type. Unfortunately, I have gotten some strange responses, including the “slow type” and the “good kind.”

I later learn that the person referring to epithelioid mesothelioma. “Epithelioid” refers to the cell structure or formation. The cells are of polygonal nature, meaning that all sides of the cell are connected or joined together. The cells are similar in shape, closely aligned or adjoining with distinct nuclei evident under microscopic examination.

Because epithelioid mesothelioma is considered to be the least aggressive but more responsive to treatment, some physicians opine that if one is going to get mesothelioma, it is the “best kind” to get. I disagree!!

Why? Because it gives the diagnosed person the impression that he or she has unlimited time to make a treatment decision. Often the diagnosed will take a wait-and-see approach. Think about this, while it may have taken 20, 30 or even 40 years for one’s mesothelioma to develop, it’s not going stop growing while you weigh your mesothelioma treatment options. I say to you, as gently as I can, there is no safety net of time.

Another subtype of mesothelioma is known as sarcomatoid mesothelioma. Sarcomatoid mesothelioma is complicated to diagnose. Pathological evaluation is difficult because the spindle-like cell structure and reaction to chemical staining mimic that of a sarcoma.

When a diagnosis of biphasic mesothelioma has been made, it is likely that biopsies were taken from different parts of the tumor. Although Dr. Pass states that this type of mesothelioma makes up about 20% to 35% of mesotheliomas, I have seen higher percentages ranging from 40 to 60 percent. This may be because of the advances made in immunohistochemical analysis as well as the surgeon’s awareness of the diseased tissue and the need for harvesting multiple sections.

Remember, a proper diagnosis is critical to choosing the best mesothelioma treatment.