Sarcomatoid Mesothelioma is a quite uncommon type of cancer caused due
to asbestos exposure. While it is difficult to diagnose Sarcomatoid
Mesothelioma, it hardly responds to any type of therapy. This is the
most serious of all asbestos-related diseases. The possibility of
finding this type of cancer is on the lips and the larynx. However, in
certain cases it may affect the oral cavity as well.
Like all other forms of mesothelioma cancers, this cancer is a fatal
disease and hardly responds to any method of treatment. Even though
radiation therapy is recommended for the treatment of these cancerous
tumors, but some of them may not be radiosensitive and may defy
radiation for treatment.
Diagnosis of Sarcomatoid Mesothelioma:
The differentiation of sarcomatoid mesothelioma from other cell tumors
by light microscopy is quite difficult. The role of
immunohistochemistry is also not well defined in its diagnosis. Since
sarcomatoid mesothelioma is not always cytokeratin-negative, the
distinction between it and sarcoma is not always possible. In this
context, the doctors undertook a study to investigate the utility of
diagnostic immunohistochemistry for distinguishing sarcomatoid
mesothelioma from its histological mimics, high-grade sarcoma and
pulmonary sarcomatoid carcinoma.
For its study, the researchers stained the mesotheliomas with
sarcomatoid components. They assessed the intensity and distribution of
staining with the help of a semi quantitative scale. Only tumors with
unequivocal staining were considered positive for tabulation. Then they
compared the immunophenotypic profiles of these tumors with 24
high-grade sarcomas. The sarcomatoid carcinomas were also stained for
thyroid transcription factor-1 (TTF-1).
The study showed that Cytokeratin 5/6 stained most of the epithelioids
but the sarcomatoids were rarely stained. On the other hand, Calretinin
and thrombomodulin each stained 70% of sarcomatoid. All 10 sarcomatoids
were negative for TTF-1. This led to the conclusion that a wide
immunophenotypic overlap exists among different sarcomatoids.
Cytokeratin and calretinin have the most value in differentiating
different sarcomatoids. Clinicopathological data, especially
information about the gross appearance of the tumor is quite important
for sarcomatoid tumors. Thus, it should be noted and carefully
correlated with microscopic and immunohistochemical findings.
Kirsten Hawkins is a asbestos and mesothelioma specialist from Nashville, TN. Visit www.asbestosblog.org/ for information on asbestos reform, mesothelioma lawsuit news, and more.
