Key Takeaways
- Sarcomatoid mesothelioma is the rarest and most aggressive of the three mesothelioma cell subtypes, accounting for 10–20% of all cases. The average life expectancy after diagnosis is approximately eight and a half months.
- Sarcomatoid cells are irregularly shaped, elongated, and spindle-shaped — with long nuclei that often contain more than one nucleus per cell. Unlike epithelioid cells, which grow in defined clusters, sarcomatoid cells migrate quickly and spread to other parts of the body.
- This subtype is extremely difficult to diagnose because it has multiple histographic subtypes and can resemble other cancers under microscopy. A tissue biopsy with histographic and cytographic analysis is required to confirm the diagnosis.
- Sarcomatoid mesothelioma most commonly develops in the pleura (tissue surrounding the lungs) and is much rarer in the abdomen or heart lining.
- Because this subtype is usually diagnosed late — after the cancer has already spread — most patients and doctors opt for palliative care focused on comfort rather than curative treatment. Surgery, chemotherapy, or radiation may be used if the cancer is caught early enough.
- Like all forms of mesothelioma, sarcomatoid mesothelioma is associated with asbestos exposure.
This type of mesothelioma is the rarest cell origin in mesothelioma cases, accounting for about
10-20% of all manifestations. Sarcomatoid cells are also present in biphasic mesothelioma, as at
least 10% of biphasic cells need to be both sarcomatoid and epithelioid. Biphasic mesothelioma
that has a larger constituency of sarcomatoid cells is notoriously more difficult to treat; this is
because sarcomatoid cells grow relatively quickly and irregularly. Sarcomatoid
mesothelioma has the worst prognosis of the three mesothelioma cell types: average life
expectancy after diagnosis is less than a year, around eight and a half months.
Here are some key distinguishing factors between sarcomatoid mesothelioma and the other types
of mesothelioma we’ve covered:
- Sarcomatoid cells themselves are irregularly shaped; they are elongated and
spindle-shaped. They have long nuclei, in which there are usually more than one in a
single cell. - The growth patterns of sarcomatoid cells lend themselves to metastasis. Unlike biphasic
and epithelioid mesothelioma, in which cancerous cells grow in clusters, sarcomatoid
cells migrate quickly to other parts of the body. - Sarcomatoid mesothelioma is difficult to treat. Again, because of the growth patterns of
the cells, they’re often spread out beyond a single area. - Along with being the rarest form of mesothelioma, it’s also the most aggressive. The
potential for metastasis, unchecked growth, and irregular shape contribute to this
“aggression.” - This type of mesothelioma is known to be associated with previous exposure to asbestos.
- Most sarcomatoid mesothelioma occurs in the pleura, or the tissues surrounding the
lungs. This cell type is much rarer in other common mesothelioma sites, like the tissues
around the abdomen or heart. - There are different histographic “subtypes” of sarcomatoid mesothelioma, which makes
diagnosis somewhat difficult. - Mesothelioma can only be diagnosed as specifically a sarcomatoid origination if patients
undergo a historiographic and cryptographic biopsy. This means that a sample of living
tissue is extracted from the mesothelioma site and sent to a lab for further testing, and
then researchers can confirm that the mesothelioma has a sarcomatoid origin. If a patient
is physically fit enough to receive a biopsy-based diagnosis, they should opt for it: it
facilitates a more contextual treatment plan by detailing the progression, growth patterns,
and metastatic tendencies of the cells of the cancer.
Treatment Options
Because it is the most aggressive type of mesothelioma, most patients
and providers opt for palliative care. If the cancer is caught especially early, and doctors
determine that it’s resectable, or able to be removed by surgery, then patients might undergo the
surgical route. Alternatively, some patients and doctors opt for chemotherapy or radiotherapy
treatments in order to shrink tumor size or alleviate pain associated with tumor growth. Usually,
though, these procedures fall under the umbrella term of “palliative care” because they seek to
provide patients comfort, not to cure or remove the cancer. Hopefully, more accurate and speedy
diagnostic techniques allow doctors to diagnose sarcomatoid mesothelioma more quickly, thus
increasing patient prognosis and treatment options.
If you or a loved one has been diagnosed with an asbestos-related disease, please call
(800)-505-6000 for legal help. For more information, fill out the form on our Contact Us page.
Frequently Asked Questions
What is sarcomatoid mesothelioma?
Sarcomatoid mesothelioma is the rarest and most aggressive of the three mesothelioma cell subtypes, accounting for approximately 10–20% of all mesothelioma cases. It is characterized by irregularly shaped, elongated, spindle-like cells that grow quickly and are prone to metastasis — spreading beyond their site of origin to other parts of the body. It carries the worst prognosis of the three subtypes, with an average life expectancy of approximately eight and a half months after diagnosis.
What makes sarcomatoid cells different from other mesothelioma cells?
The key differences are shape, growth pattern, and treatability:
- Shape — sarcomatoid cells are elongated and spindle-shaped with long nuclei (often more than one per cell), unlike the uniform, round clusters of epithelioid cells
- Growth pattern — rather than growing in contained clusters, sarcomatoid cells migrate quickly and spread to distant parts of the body
- Treatment response — sarcomatoid cells are the most resistant to treatment of all three subtypes, making surgery, chemotherapy, and radiation less effective
- Diagnosis — the irregular shape and multiple histographic subtypes make sarcomatoid mesothelioma harder to identify and easier to misdiagnose as another type of cancer
Why is sarcomatoid mesothelioma so difficult to diagnose?
Several factors make diagnosis challenging. The cells have multiple histographic subtypes that can look different under microscopy, and they can resemble other types of cancer — making it easy to misclassify. A definitive diagnosis requires a tissue biopsy with histographic and cytographic analysis, where a sample of living tissue is extracted from the mesothelioma site and examined in a laboratory. This level of analysis reveals the progression, growth patterns, and metastatic tendencies of the cells — information that is critical for developing a treatment plan.
Where does sarcomatoid mesothelioma typically develop?
Sarcomatoid mesothelioma most commonly develops in the pleura — the tissue lining surrounding the lungs. While mesothelioma can also occur in the abdomen (peritoneal), heart (pericardial), and testicles, the sarcomatoid cell type is much rarer in these other locations and is predominantly found in pleural cases.
What are the treatment options for sarcomatoid mesothelioma?
Because sarcomatoid mesothelioma is typically diagnosed after the cancer has already spread, most treatment plans focus on palliative care — managing symptoms and improving quality of life rather than curing the disease. Treatment options may include:
- Surgery — only if the cancer is caught early enough and doctors determine the tumor is resectable (removable)
- Chemotherapy — used to shrink tumors or slow their growth
- Radiation therapy — used to alleviate pain and pressure caused by tumor growth
In most cases, these treatments are considered palliative rather than curative. The hope is that advances in diagnostic speed and accuracy will allow earlier detection, which could expand treatment options and improve outcomes.
How does sarcomatoid mesothelioma compare to the other subtypes?
The three mesothelioma cell subtypes, ranked from best to worst prognosis:
- Epithelioid (50–70% of cases) — grows slowly in defined clusters, easiest to diagnose and treat, best prognosis
- Biphasic (20–30% of cases) — contains both epithelioid and sarcomatoid cells, prognosis depends on which cell type dominates
- Sarcomatoid (10–20% of cases) — grows quickly and irregularly, most treatment-resistant, worst prognosis (~8.5 months)
Sarcomatoid cells are also present in biphasic mesothelioma — the higher the proportion of sarcomatoid cells in a biphasic tumor, the worse the prognosis.
What should I do if I’ve been diagnosed with sarcomatoid mesothelioma?
If you or a loved one has been diagnosed with sarcomatoid mesothelioma or another asbestos-related disease, understanding your treatment options and legal rights is an important step — even with a challenging prognosis, there are options available to help manage the disease and pursue compensation for asbestos exposure. Call (800) 505-6000 or fill out our contact form for a free consultation.
