Overview

Mesothelioma is a rare and aggressive cancer that develops in the mesothelium — the thin layer of tissue that covers most internal organs. The vast majority of mesothelioma cases are caused by exposure to asbestos fibers.

Types of Mesothelioma

Pleural mesothelioma (lungs) accounts for approximately 80% of all diagnoses. Fibers inhaled into the lungs migrate to the pleural lining and cause cellular damage over decades.

Peritoneal mesothelioma (abdomen) is the second most common type, representing roughly 15–20% of cases. It develops in the lining of the abdominal cavity.

Pericardial mesothelioma (heart) and testicular mesothelioma are extremely rare.

Latency Period

Mesothelioma has an exceptionally long latency period — typically 20 to 50 years between first asbestos exposure and diagnosis. This means many patients are diagnosed decades after their occupational exposure ended.

Who Is at Risk

Occupations with historically high asbestos exposure include:

  • Insulators and pipe coverers
  • Boilermakers
  • Pipefitters and plumbers
  • Electricians
  • Maintenance workers at industrial facilities
  • Power plant workers
  • Shipyard workers
  • Construction trades workers

Iowa had significant industrial asbestos use in power plants, chemical facilities, refineries, and manufacturing through the 1980s.

Prognosis

Mesothelioma is typically diagnosed at an advanced stage due to its long latency and non-specific early symptoms. Median survival after diagnosis ranges from 12 to 21 months depending on stage and cell type, though some patients — particularly those diagnosed early with epithelioid cell type — achieve significantly longer survival with aggressive treatment.