Small Cell Mesothelioma
Small cell mesothelioma is an extremely rare subtype that can be mistaken for small cell lung cancer. As the name suggests, cancer cells in these tumors are smaller than cells in other forms of mesothelioma.
Written by Karen Selby, RN Edited By Walter Pacheco Medically Reviewed By Dr. Rupesh Kotecha
Asbestos.com is the nation’s most trusted mesothelioma resource
The Mesothelioma Center at Asbestos.com has provided patients and their loved ones the most updated and reliable information on mesothelioma and asbestos exposure since 2006.
Our team of Patient Advocates includes a medical doctor, a registered nurse, health services administrators, veterans, VA-accredited Claims Agents, an oncology patient navigator and hospice care expert. Their combined expertise means we help any mesothelioma patient or loved one through every step of their cancer journey.
More than 30 contributors, including mesothelioma doctors, survivors, health care professionals and other experts, have peer-reviewed our website and written unique research-driven articles to ensure you get the highest-quality medical and health information.
About The Mesothelioma Center at Asbestos.com
- Assisting mesothelioma patients and their loved ones since 2006.
- Helps more than 50% of mesothelioma patients diagnosed annually in the U.S.
- A+ rating from the Better Business Bureau.
- 5-star reviewed mesothelioma and support organization.
Testimonials
My family has only the highest compliment for the assistance and support that we received from The Mesothelioma Center. This is a staff of compassionate and knowledgeable individuals who respect what your family is experiencing and who go the extra mile to make an unfortunate diagnosis less stressful. Information and assistance were provided by The Mesothelioma Center at no cost to our family.LashawnMesothelioma patient’s daughter
How to Cite Asbestos.com’s Article
APA
Selby, K. (2023, February 22). Small Cell Mesothelioma. Asbestos.com. Retrieved June 1, 2023, from https://www.asbestos.com/mesothelioma/small-cell/
MLA
Selby, Karen. "Small Cell Mesothelioma." Asbestos.com, 22 Feb 2023, https://www.asbestos.com/mesothelioma/small-cell/.
Chicago
Selby, Karen. "Small Cell Mesothelioma." Asbestos.com. Last modified February 22, 2023. https://www.asbestos.com/mesothelioma/small-cell/.
What Is Small Cell Mesothelioma?
Small cell mesothelioma is as a subtype of the epithelial cell type. But many mesothelioma tumors with small cell features are biphasic. That means the tumors contain a combination of epithelial and sarcomatoid cells.
This type of mesothelioma grows in a pattern like small cell carcinoma. But the tumors do not display the stream, ribbon or rosette patterns in the subtype of lung carcinoma.

Small cell mesothelioma tumors grow in the peritoneum (abdominal lining). They can also arise in the pleura (lung lining) or the pericardium (heart sac).
Most of these tumors are not made up entirely of small cells. Instead, they often also contain normal mesothelioma cells and other assorted neoplastic cells.
Roughly half or more of all cells in a tumor should display a small cell pattern for the tumor to qualify as this type.
Small Cell Mesothelioma Facts
- Extremely rare variant of mesothelioma
- Misdiagnosed as other types of cancer
- Differentiated using immunohistochemistry
- Doctors use standard mesothelioma treatment approaches

Diagnosis of Small Cell Mesothelioma
Diagnosing this cell type is difficult. The reason is the cells look like other small cell neoplasms. Doctors must run immunohistochemical tests to differentiate between the diseases.
Small cell mesothelioma often resembles:
- Small cell lung carcinoma (SCLC)
- Desmoplastic small round cell tumor (DSRCT)
- Peripheral neuroectodermal tumor (PNET)
- Lymphoma
A single biopsy may not always contain a representative sample of the cells in the entire tumor. In one study, small cells made up 80% to 100% of the biopsy material. But only 15% to 20% of the full tumor. Doctors may retrieve several samples to make an accurate mesothelioma diagnosis.
After immunohistochemical staining, the tumor cells will test positive for different compounds. This helps the medical team narrow the diagnosis. Small cell mesothelioma and small cell carcinoma have similar-looking cells. But each disease reacts to different chemical markers.
Diagnosing the right type is vital because different cancers respond to different treatments.
Small Cell Mesothelioma Treatment and Prognosis
Developing a standard of treatment for small cell mesothelioma is difficult. Doctors have not reported many cases. So doctors must rely on standard mesothelioma treatment approaches.
Small cell lung cancer (SCLC) is more aggressive than other types of lung cancer. It is unclear if prognosis for small cell mesothelioma is different from other epithelial mesotheliomas.
Researchers in 2020 said small cell mesothelioma has similar cell morphology to SCLC. But it has a different immunohistochemical profile. They concluded that the rare variant has a poor prognosis with a mean survival of about 8 months.