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Epithelioid Mesothelioma & Adenocarcinoma: Similar but Not the Same

Epithelioid mesothelioma is a rare disease, thought to afflict between 2,000 and 3,000 people per year. As it is so rare, cases of malignant mesothelioma are sometimes misdiagnosed as a similar but more common cancer known as adenocarcinoma. While the two diseases do have some commonalities, the causes and treatments are very different. It is important for patients and their doctors to be aware of the differences between the diseases and the methods to correctly discern mesothelioma from adenocarcinoma.

Similarities between Epithelioid Mesothelioma & Adenocarcinoma

Epithelioid mesothelioma and adenocarcinoma both occur in the epithelial cells. Epithelial cells form the layers of cells that create barriers between parts of the body, including the:

skin,
lungs,
intestines, and
protective membranes surrounding internal organs.

Depending on their location, both diseases may have similar symptoms, such as bloating, shortness of breath, and localized pain. Victims of either disease may also have recurring fever and general tiredness. The similarity of locations within the body and the similarity of symptoms contribute to misdiagnosis.

Differences between Epithelioid Mesothelioma & Adenocarcinoma

While both of these diseases occur in epithelial linings, the area of the lining where they occur is different. Mesothelioma is caused by the inhalation or ingestion of microscopic asbestos fibers. Over time, these fibers puncture the walls of the internal organs and become “trapped” in the outer epithelial lining, since the body cannot break asbestos fibers down.

Conversely, adenocarcinoma almost always occurs in the inner epithelial lining. Adenocarcinoma also differs from mesothelioma in that its harder to determine its cause. Like many other cancers, adenocarcinoma can develop due to factors such as smoking, unhealthy eating and exercise habits, and genetics, as well as asbestos exposure. On the other hand, smoking is never the cause of mesothelioma.

Distinguishing Location and Cause for Diagnosis

The distinction between epithelioid mesothelioma and adenocarcinoma cannot be made by standard x-rays or CAT scans; a biopsy is required. Cases where the fibrous characteristics of mesothelioma caused by asbestos are not clear from the biopsy often lead to a misdiagnosis of adenocarcinoma. Whenever there is a suspicion of mesothelioma, especially if the patient has a prior history of asbestos exposure, a combination of three tests should be done to rule out other possible diseases:

immunocytochemistry
electron microscopy
and biochemical analysis of biopsy material

Other tests often used to make a correct diagnosis of diffuse epithelial malignant mesothelioma can include extra-pleural pneumonectomy, video-assisted thoracoscopic biopsy of the left pleura, diaphragm, and lung, pleural fluid cytologic study, and immunohistochemical stains.
When in-depth testing is done, the rates of mesothelioma diagnosis actually increase, meaning many epithelioid mesothelioma victims avoid being misdiagnosed with related, but different, diseases.

Why Correct Diagnosis is Critical

Although mesothelioma and adenocarcinoma are both cancers, the treatments and patient outcomes for the diseases are dissimilar. Adenocarcinoma is highly treatable and tends to be a less aggressive cancer, meaning that patient outcomes are more positive. In many cases, surgery for this disease is delayed to begin pre-operative chemotherapy or radiation treatments. With mesothelioma, this course of action is rarely recommended; though chemotherapy and radiation are commonly used as mesothelioma treatments, due to the aggressiveness of the cancer, most physicians agree surgery, when possible, should not be delayed.

If you have reason to believe that you have been exposed to asbestos at any time in the past, especially if you have been diagnosed with adenocarcinoma, getting a second medical opinion is recommended for accurate diagnosis. If you have been diagnosed with epithelial mesothelioma, finding the best treatment as well as legal representation is imperative. Clapper, Patti, Schweizer & Mason, mesothelioma attorneys exclusively practicing asbestos litigation for over 30 years, can help you determine a course of action for treatment and other considerations to provide for the needs of you and your loved ones after asbestos exposure.