Mesothelioma Diagnosis May Include Surgical Techniques

Mesothelioma Diagnosis

Mesothelioma Diagnosis Through Tissue and Fluid Samples

The removal of cell or tissue samples for examination under a microscope is called a biopsy. Your doctor may perform a biopsy of your tissues and fluids if he or she suspects that you have mesothelioma.

In a needle or fine–needle biopsy for pleural mesothelioma, a needle is inserted into the chest cavity to remove fluid for sampling purposes. The same method may be used to extract fluid samples from the abdomen or stomach. Microscopic and chemical examination of the fluid determines whether cancer cells are present. Special stains or electron microscopy can aid tissue analysis. Common stains include acid–Schiff diastase, hyaluronic acid, mucicarmine, CEA, and Leu M1.

Technicians may find that it is difficult to diagnose mesothelioma from needle biopsies, especially with small samples. For example, the cells associated with pleural mesothelioma may look a lot like lung cancer cells. One technique that may distinguish mesothelioma cells is to look at the cell genes. Researchers at Brigham and Women’s Hospital in Boston, Massachusetts, found that analyzing certain gene expression ratios was an accurate and inexpensive way to distinguish between pleural mesothelioma and lung cancer (Cancer Res. 2002 Sep 1; 62(17): 4963–7).

Surgical Techniques to Obtain Mesothelioma Tissue Samples

Doctors may obtain a patient’s tissue samples through surgical techniques. In “thoracoscopy,” a thin telescopic instrument (thoracoscope) fitted with a lighting system is inserted through a puncture in the chest wall. The tumor is then sampled with a forceps–like tool.

A mediastinoscopy is a method of looking at the tissues and organs in the mediastinum, which is the chest cavity behind the breastbone that lies between the lungs. First, a tube is inserted in the trachea. Next, the surgeon makes an incision in the chest, inserting a narrow tube or mediastinoscope. The lighted mediastinoscope allows the surgeon to insert tools to collect tissue samples. The purpose of the mediastinoscopy is to show whether tumors have spread to the mediastinal nodes (the lymph nodes in the mediastinum).

Combining Sampling with Other Mesothelioma Diagnostic Methods

A biopsy is only one means of diagnosing mesothelioma. Your doctor will likely combine this procedure with imaging tests such as x–rays and CT scans, which may also help determine whether tumors have spread. See the discussion of Mesothelioma Diagnosis and Imaging.