What Is Mesothelioma? Types, Causes, and the Latency Period Explained

By:  Christopher M. Placitella Jul 14, 2026

Updated: July 14, 2026

Quick Answer: Mesothelioma is a rare, aggressive cancer that affects the lining of vital organs — most often the lungs — and is almost always caused by asbestos exposure. There are four types: pleural (about 75% of cases), peritoneal (15–20%), pericardial (less than 1%), and testicular (extremely rare). The latency period between first asbestos exposure and diagnosis is typically 15 to 50 years, which is why many people diagnosed today were exposed decades ago in shipyards, construction, or manufacturing jobs. Cohen, Placitella & Roth has represented mesothelioma patients and families for more than 40 years and offers a free consultation.

Through decades of representing mesothelioma patients, we have learned that understanding this disease is the first step toward making informed decisions. Mesothelioma is a rare and aggressive cancer that affects the lining of vital organs, most often the lungs. Unlike lung cancer, which starts inside the lung tissue and may arise from a variety of causes unrelated to asbestos exposure, mesothelioma is almost always caused by exposure to asbestos fibers.

The Four Types of Mesothelioma

Mesothelioma is classified by the location in the body where it develops. Each type behaves differently and calls for its own approach to diagnosis and treatment. Recognizing the early symptoms of mesothelioma can also make a meaningful difference in how quickly a diagnosis is reached.

  • Pleural mesothelioma — affects the lining around the lungs; the most common form, making up approximately 75% of cases
  • Peritoneal mesothelioma — affects the lining of the abdomen; roughly 15% to 20% of cases
  • Pericardial mesothelioma — affects the lining around the heart; less than 1% of cases and extremely rare
  • Testicular mesothelioma — affects the lining around the testicles; also extremely rare

Why the Latency Period Matters

Based on our clients’ experiences, mesothelioma often develops 15 to 50 years after asbestos exposure. Many people diagnosed today were first exposed decades ago, in the 1960s, 1970s, or 1980s, while working in shipyards, construction sites, manufacturing plants, or other industrial environments. Others were exposed through asbestos-contaminated products, such as talc-based powders.

Mesothelioma is rare, but its causes are well understood. If you or a loved one worked with or around asbestos, it is important to recognize the risks, understand the stages of mesothelioma, and discuss screening with your healthcare provider.

How Mesothelioma Differs From Lung Cancer

Lung cancer starts inside the lung tissue itself and can arise from a number of causes, including smoking. Mesothelioma, by contrast, affects the lining of organs, most often the lungs, and is almost always linked to asbestos exposure. Because the two diseases develop differently, they are also treated differently — our asbestos-related lung cancer attorneys and mesothelioma attorneys handle these cases separately for exactly that reason.

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Frequently Asked Questions About Mesothelioma

  • What is mesothelioma?

    Mesothelioma is a rare and aggressive cancer that affects the lining of vital organs, most often the lungs. Unlike lung cancer, which starts inside the lung tissue and may arise from a variety of causes unrelated to asbestos exposure, mesothelioma is almost always caused by exposure to asbestos fibers.

  • What are the four types of mesothelioma?

    The four types are pleural (affecting the lining around the lungs, about 75% of cases), peritoneal (affecting the lining of the abdomen, about 15–20%), pericardial (affecting the lining around the heart, less than 1%), and testicular (affecting the lining around the testicles, extremely rare).

  • How long after asbestos exposure does mesothelioma develop?

    Mesothelioma often develops 15 to 50 years after asbestos exposure. Many people diagnosed today were first exposed in the 1960s, 1970s, or 1980s while working in shipyards, construction sites, manufacturing plants, or other industrial environments.

  • How is mesothelioma different from lung cancer?

    Mesothelioma affects the lining of organs, most often the lungs, while lung cancer starts inside the lung tissue itself. Mesothelioma is almost always caused by asbestos exposure, while lung cancer can arise from multiple causes, including smoking. Treatment approaches differ significantly.

Talk to Cohen, Placitella & Roth About Your Mesothelioma Diagnosis

If you or a loved one has been diagnosed with mesothelioma, you do not have to face it alone. Our mesothelioma attorneys have represented patients and families for more than 40 years. Contact Cohen, Placitella & Roth for a free consultation. Call us at (888) 324-7683 or contact us online. We work on a contingency fee basis. You pay nothing unless we recover compensation for you.


Attorney Advertising. Prior results do not guarantee a similar outcome. This article is for informational purposes only and does not constitute legal or medical advice. Consult a qualified healthcare provider regarding diagnosis and treatment, and a qualified attorney regarding your legal rights. Cohen, Placitella & Roth, P.C. is licensed to practice in New Jersey, Pennsylvania, and other jurisdictions, and represents clients nationwide with qualified co-counsel.

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