Mesothelioma Information

Epithelioid mesothelioma is the most common type of mesothelioma cancer cell.  In order to diagnose a case of epithelioid mesothelioma, a biopsy is required.  A type of diagnostic surgery, a biopsy involves the removal of a section of suspect tissue for examination by a histopathologist.

Epithelioid mesothelioma has a unique cellular pattern that is somewhat tubular.  When viewed under high magnification, epithelioid mesothelioma cancer cells have a fairly distinct nucleus.

Although the tubular cellular pattern associated with epithelioid mesothelioma is considered to be unique, there are a number of other cancers that can take on a similar appearance.  When such cancers occur in the mesothelium, it could potentially foster the misdiagnosis of the disease.  A cancer of the mesothelium most commonly confused with epithelioid mesothelioma is adenocarcinoma.

Epithelioid Mesothelioma and Adenocarcinoma

Adenocarcinoma is a type of epithelial cancer that originates in the body's glandular tissue.  Adenocarcinoma often presents itself as a benign glandular tumor (adenoma) that develops into a malignant state over time.

Mesothelioma affects a type of serous tissue called the mesothelium, the protective lining of the body's largest cavities.  The mesothelium is a type of epithelium, specialized tissue that separates different "environments" in the body.  For example, the skin is a type of epithelial tissue because it separates the outside environment of the body from the inside environment of the body.

Cancer of the epithelium is commonly referred to as carcinoma.  The two most common types of carcinoma are squamous cell carcinoma and adenocarcinoma.  Adenocarcinoma is typically found in the lung, accounting for an approximate 30 to 40% of all lung-based carcinomas.  It is common for lung-based adenocarcinomas to metastasize, spreading to the epithelial tissue lining of the lungs (mesothelium of the lungs; the pleura) and thus taking on the appearance of epithelioid mesothelioma.

Epithelioid mesothelioma and adenocarcinoma are both rooted in the epithelial tissue, and as such, have a similar cellular structure. Histopathologists can often have a difficult time distinguishing between adenocarcinoma and epithelioid mesothelioma for this very reason.  Chemical staining of a section of suspect tissue will often yield the correct diagnosis; however, chemical staining of epithelioid mesothelioma cells and adenocarcinoma cells sometimes elicits similar results.

Knowledge of a family history can often help aid in distinguishing between adenocarcinoma and epithelioid mesothelioma.  If a patient has a family history of carcinoma, it is more likely that they suffer from a variant of the disease. If a patient has a history of asbestos exposure, it is more likely that they suffer from epithelioid mesothelioma.

Sarcomatoid and Biphasic Mesothelioma

There are three histological categories of mesothelioma cancer cells:  epithelioid mesothelioma, sarcomatoid mesothelioma and biphasic mesothelioma.

Sarcomatoid mesothelioma is the least common type of mesothelioma cancer cell.  Like epithelioid mesothelioma, sarcomatoid mesothelioma has a somewhat unique cellular pattern when viewed under high magnification.

Biphasic mesothelioma is the second most common type of mesothelioma cancer cell.  Unlike sarcomatoid and epithelioid mesothelioma, biphasic mesothelioma does not have a unique cellular pattern unto itself; rather, biphasic mesothelioma consists of a mixture of epithelioid and sarcomatoid mesothelioma cells.