Once a brain tumor is removed or biopsied, how long does it take to identify how aggressive a tumor it is?
The tissue removed during surgery is reviewed immediately by the pathologist using a technique called “frozen sectioning.” This provides the pathologist with a rough idea as to whether the tissue contains the tumor and whether the tissue is adequate to make a diagnosis. However, a final diagnosis requires more detailed examination and a process called “paraffin embedding and sectioning,” which takes one to two days. This yields material that is generally adequate to determine if the tumor is aggressive or low-grade, and which type of tumor it is. Additional testing is occasionally performed to determine if the tumor contains markers that predict its responsiveness to chemotherapy, and these tests generally take one week.
