Desmoplastic Mesothelioma

A subtype of malignant mesothelioma is desmoplastic mesothelioma, of the sarcomatoid cell type mesothelioma.

The term “desmoplastic” refers to the tendency of the tumor to grow fibrous tissue. There is the chance that desmoplastic mesothelioma may initially be misdiagnosed as pleural fibrosis.

Features Of Desmoplastic Mesothelioma

Desmoplastic mesothelioma is a subtype of the rare and deadly sarcomatoid mesothelioma. The cells of sarcomatoid tumors are known for their spindle-like shapes and their low cellular adhesion. This particular subtype has a very poor prognosis. 

During histologic analysis, it is seen that desmoplastic mesothelioma cells are not well-differentiated and that the presence of fibrous or dense connective tissue is the defining characteristic of this type of cancer. The rarity of this variation is only present in approximately 5%-10% of total malignant mesothelioma cases.

Diagnosing Cases Of Desmoplastic Mesothelioma

To diagnose desmoplastic mesothelioma, a biopsy must be taken from the tumor. Frequently enough tissue is gathered to make a review and confirm the diagnosis if needed. A large biopsy sample is particularly important to diagnosing desmoplastic mesothelioma since the regions of fibrous tissue can obscure cell variations that are crucial to an accurate diagnosis.

Sometimes, due to the nature of the tumors, cases of desmoplastic mesothelioma are not diagnosed correctly initially. They are occasionally misdiagnosed as pleural fibrosis, rheumatoid disease, fibrous pleurisy, and even spindle cell sarcoma.

Luckily there are specific diagnostic criteria that are used to positively confirm the diagnosis.

Diagnostic Criteria For Desmoplastic Mesothelioma

  • 50% or more of the tumor forms fibrous nodules on a frequent basis
  • Neoplastic spindle cells have spread to the chest wall or lung tissue
  • Non-fibrous regions feature cellularity with sarcomatoid features
  • There has been metastasis in neighboring fat, skeletal, or lung tissue

One of the challenges associated with diagnosing desmoplastic mesothelioma is that it will frequently resemble benign fibrous tissues. However, scans like CT or MRI can help pathologists pinpoint metastasis and even diagnose in real time.

Desmoplastic Mesothelioma Symptoms

The primary feature of desmoplastic malignant mesothelioma is a higher-than-normal level of connective or fibrous tissue.

These areas can end up producing symptoms similar to pulmonary fibrosis, like persistent chest pain or a fluid build-up in the lungs or chest. That being said, most patients diagnosed with pleural mesothelioma are admitted with shortness of breath and most patients diagnosed with peritoneal will experience abdominal pain.

Treatment Of Desmoplastic Mesothelioma

Often the prognosis for a diagnosis of desmoplastic mesothelioma is not good, just as other diagnoses of sarcomatoid cell types and subtypes. This can be exacerbated by the difficulty of the disease to diagnose, leading to the discovery of cancer at an advanced stage. Life expectancy for patients with this subtype is generally a year or less. A study from the 1990s showed a mean survival time from symptoms to death of only 5.8 months.