A biopsy is defined as “an examination of tissue removed from a living body to discover the presence, cause, or extent of a disease.” In diagnosing mesothelioma, a biopsy is considered the “gold standard” meaning it is the single most important procedure when arriving at an accurate diagnosis. Although mesothelioma can, in some cases, be diagnosed from testing fluids (pleural effusion or ascites), the biopsy is considered the most reliable diagnostic tool.
A tissue biopsy simply means that the clinician removes a part of the suspected tissue (suspected mesothelioma) for closer examination. Most biopsies are needle biopsies, meaning a needle is used to access the suspicious tissue. Sometimes a CT-guided biopsy will be used. In this case, the patient rests in a CT-scanner and the scanner’s images help doctors determine the exact position of the needle.
In some cases where possible pleural mesothelioma is being investigated, the needle can create a small hole in the lung which can cause air to fill the space between the lung and chest wall. This is called a pneumothorax and, depending on the size, could require treatment such as using a catheter to vacuum out the trapped air.
Endoscopic biopsy is commonly used in mesothelioma diagnosis. An endoscope is a thin instrument that has a light and a lens (or video camera) and usually has a tool to remove tissue samples. Endoscopes have different names depending on the part of the body where they’re used.
Suspected Pleural Mesothelioma – Thoracoscope for thoracoscopy:
An endoscope called a thoracoscope is used to look at areas inside the chest and at the pleura and take tissue samples for biopsies. Thoracoscopy is generally performed in the operating room under general anesthesia. The doctor inserts the thoracoscope through one or more small incisions made in the chest. Thoracoscopy can also be used as part of a procedure to remove fluid from the chest. This is called pleurodesis.
Suspected Peritoneal Mesothelioma – Laparoscope for laparoscopy
An endoscope called a laparoscope is used to look inside the abdomen and take a sample (biopsy) of any peritoneal tumors. This is usually done in the operating room while the patient is under general anesthesia. The laparoscope is inserted into the abdomen through small abdominal incisions.
If a needle or endoscopic biopsy is not sufficient, doctors may recommend a more invasive surgical biopsy. Here, either open or laparoscopic surgery may be necessary to obtain hard-to-reach tissue.
Once biopsy material is obtained, it is given to a pathologist so that this doctor can use various tools and tests to identify precisely what tissue or cancer has been removed from the patient.