Biopsies are the only way to confirm the mesothelioma. Mesothelioma biopsies involve removing a fluid or tissue sample for analysis. Through testing, doctors confirm the diagnosis, stage, cell type and type of mesothelioma. Once the diagnosis is confirmed through biopsy, a medical team can determine treatment options.
There are four types of biopsies that are commonly used for mesothelioma diagnosis.
- Fluid Drainage: Fluid drainage is the least invasive biopsy option. This test collects fluid from pleural, peritoneal or pericardial effusions using a needle or catheter. The fluid sample may be drained through thoracentesis, an outpatient procedure. However, in most instances, a fluid sample is not adequate to confirm a mesothelioma diagnosis.
- Needle biopsies: Doctors use a needle biopsy to extract a tissue sample from an affected area. The tissue samples are often taken from the pleura (lining of the lung) or a lymph node.
- Surgical camera-assisted biopsies: In a camera-assisted biopsy, a small tube with a camera is inserted into an affected area to locate and retrieve a tissue sample for analysis. Types of camera-assisted biopsies used for mesothelioma include thoracoscopy, laparoscopy and mediastinoscopy.
- Open surgical biopsies: Surgical biopsies are the most invasive biopsy used for mesothelioma diagnosis. This option is used if tumors are difficult to reach with less invasive procedures. Surgical biopsies used for mesothelioma include thoracotomy and laparotomy.
Mesothelioma Blood Tests and Biomarkers
Blood tests can be used to look for mesothelioma biomarkers, or substances in the blood that suggest the presence of malignant mesothelioma.
For example, healthy mesothelial cells produce normal levels of mesothelin, but malignant mesothelial cells produce higher levels of the protein. Blood tests can detect increased levels of mesothelin and aid diagnosis.