Mesothelioma Histology

Mesothelioma histology involves the anatomical study of mesothelioma cells, including sarcomatoid, desmoplastic (a variant of sarcomatoid), epithelial and biphasic cells. Scientists and medical professionals research and study mesothelioma cells to improve mesothelioma histopathology, which helps to diagnose mesothelioma through identifying anatomical structures of mesothelioma cells under a microscope.

Histology, Histopathology and Mesothelioma

Histology refers to the microscopic anatomical study of cells and tissues belonging to plants and animals. Sampled cells and tissues are observed under a microscope (a light or electron microscope) while the microscopic anatomy of the specimen is studied. A specimen must be "fixed" to preserve the sample from degradation. Fixing chemicals can include formaldehyde, glutaraldehyde, osmium tetroxide or uranyl acetate. The specimen is typically "stained" using a variety of chemicals, which allows histotechnicians to more clearly observe and study the sample.

Histopathology is the microscopic study of diseased cells and tissue in order to accurately diagnose cancer and other diseases. To diagnose various forms of cancer and disease a histopathologist examines a sample from a biopsy (an extracted specimen of the tumor being diagnosed) under a microscope and looks for anatomical indicators. A histopathologist diagnosing a malignant mesothelioma tumor will look for anatomical indicators on the tissue sample to designate whether the mesothelioma tumor is epithelial, sarcomatoid, desmoplastic or biphasic.

Mesothelioma Histology Types

Approximately 50 to 70 percent of malignant mesotheliomas are epithelial, around 20 to 35 percent are biphasic, and 7 to 20 percent are sarcomatoid. Epithelial cells are known for a well-defined and uniform shape. They can closely resemble cells of another form of cancer known as adenocarcinoma, which can complicate the diagnostic process for histopathologists. There are many subtypes of epithelial mesothelioma, such as tubulopapillary, microcystic and well-differentiated papillary mesotheliomas.

Sarcomatoid cells are known for their elongated spindle shape, which are typically irregular and not uniform in shape. These cells often overlap one another. Considered a variant of sarcomatoid mesothelioma, desmoplastic mesothelioma is sometimes considered the most difficult mesothelioma to diagnose. When a desmoplastic mesothelioma invades or spreads to other tissue, the cells tend to look very bland and this can lead to the mesothelioma being misdiagnosed as benign fibrous tissue. Mesothelioma experts agree that this form of mesothelioma should not be diagnosed with a needle core biopsy.

Mesothelioma cells that are biphasic contain both epithelial and sarcomatoid cells. These cells form in groups of similar cells and do not exhibit a uniform mixture. Because of this factor, several samples are collected from different locations within the tumor during a biopsy. This helps the histopathologist to accurately provide a mesothelioma diagnosis.

Considering the subtle differences that histopathologists must assess, diagnosing the type of mesothelioma can be difficult. A major contributing factor to this difficulty is the challenge in differentiating mesothelioma from adenocarcinoma (a cancer that originates in glandular tissue). Learning more about the diagnostic process can help mesothelioma patients to understand their condition and their treatment options. To learn more about mesothelioma histology, diagnosis and treatment options, please fill out this form to receive a complimentary packet in the mail.