From the blog

Epithelioid Mesothelioma And Reactive Mesothelial Hyperplasia

Published: March 5, 2018

The type of mesothelioma can be based upon where the cancer is located in the body, but it can also be based upon cell type – meaning, which cell has turned cancerous. The body has many different types of cells including epithelial, which make up the lining of the mesothelium (where mesothelioma develops). When these cells become cancerous, the cell patterns become biphasic or sarcomatoid, but more of than not, the cell pattern is epithelial.

Reactive Mesothelial Hyperplasia is when mesothelial cells reproduce quickly, causing enlarged organs or tissue. Hyperplasia is an indicator of the early stages of cancer. The distinction between epithelioid mesothelioma and mesothelial hyperplasia has been consistently challenging for scientists. A recent study published in Oncology Letters assessed certain diagnostic utilities by using immunotherapy order to better distinguish between the two.

To do this, the following was examined:

  • Survivin – a protein expressed in large amounts in most tumors and inhibits apoptosis (cell death)
  • BAP-1 – BRCA1 associated protein that is a specific biomarker for differentiating mesothelioma from reactive mesothelial proliferations
  • Ki-67 – a protein that aids in rapid cell growth or proliferation

The study investigated 78 cases of epithelioid mesothelioma and 80 cases of reactive mesothelial hyperplasia for Survivin, BAP-1, and Ki-67. Results are as follows:

Sensitivity (%) Specificity (%)
Survivin 67.7 100
BAP-1 66.2 100
Ki-67 85.1 87.5


The combination of Survivin and BAP-1 produced the highest accuracy (95%), along with 89% sensitivity and 100% specificity. The study concludes that to better distinguish between epithelioid mesothelioma and reactive mesothelial hyperplasia, a combination of Survivin and BAP-1 is recommended.

One of the most important factors in treating mesothelioma is being able to correctly diagnose the illness accurately, and if possible, quickly. Symptoms of mesothelioma are similar to other common, non-life threatening illnesses and unfortunately, can be diagnosed as such. Mesothelioma treatments are often times ineffective, but show better results the earlier the cancer is caught.



Kushitani, K et. al. “Utility of Survivin, BAP1, and Ki-67 immunohistochemistry in distinguishing epithelioid mesothelioma from reactive mesothelial hyperplasia,” Oncology Letters (2018 March). [Link]

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