When people think about cancer care, they often picture the doctors and specialists they meet face to face. But behind every diagnosis is a dedicated team of laboratory professionals and pathologists working behind the scenes to carefully analyze a biopsy and provide the information needed to guide treatment.  

Dr. Robert Koscick, medical director of the pathology lab at Woman’s Hospital and a specialist in breast and gynecologic cancers, explains how pathologists determine if you have cancer and how a tiny piece of tissue becomes an important roadmap for personalized cancer care. 

What is a pathologist? 

Although you’ll likely never meet the pathologists, their work is essential to every cancer diagnosis. Pathologists are medical doctors who specialize in diagnosing cancer by studying the tissue that your physician has removed.  

Pathologists examine the tissue under a microscope to determine whether cells are normal, abnormal, or cancerous. They can also identify the specific type of cancer and figure out how aggressive it appears.  

What happens after my biopsy goes to the lab? 

Once the lab receives a biopsy, a team of lab professionals carefully prepares the tissue so the pathologist can examine it. 

Preparation 

The first step is to put the tissue in formalin, a preservative that helps the tissue maintain its structure. This is important because tissue begins to die after it’s removed from your body. Formalin essentially freezes time to preserve the tissue so the pathologist can get an accurate snapshot of what it looked like when it was removed. 

Next, the lab team places the preserved tissue in a small plastic container called a cassette and sends it through a tissue processor. During this process, the tissue gets embedded in paraffin wax to give it enough support to be cut into numerous extremely thin sections. Examining multiple levels of the tissue gives the pathologist a more complete picture and increases the chance of finding something important that may not be visible in a single section. 

The thin slices of tissue are then carefully placed onto glass slides. The wax dissolves and the tissue gets stained pink and purple to make different structures easier to see. Lastly, the slides are then covered with a thin protective coverslip and delivered to the pathologist. 

Examination 

To determine whether an abnormality is benign or malignant, pathologists examine the tissue under a microscope. They look closely at the cells and their patterns, how they’re arranged, and how they interact with the surrounding tissue.  

Healthy cells typically follow a predictable pattern, but cancer cells behave very differently. For instance, cancer cells often have larger nuclei than healthy cells. They also divide much quicker than healthy cells and invade surrounding tissue.  

Pathologists use all this information to determine if the cells are cancerous, and, if so, what type and grade the cancer is. Depending on the type of cancer, they might also perform a few extra tests. For example, breast cancer tissue may be tested for hormone receptors, which can help determine whether hormone therapy may be an effective part of treatment. 

Results 

Once the pathologists have thoroughly analyzed the tissue and completed any necessary testing, they put their findings into a pathology report. In many ways, the pathology report acts as a roadmap. It contains a diagnosis, cancer type, cancer grade, and information that can help your care team understand the cancer and determine the best treatment approach.  

What’s the difference between type, grade, and stage? 

Although cancer type, grade, and stage are related, they each describe something different. 

Type describes where the cancer began and the kind of cells involved. For example, two common breast cancer types are ductal carcinoma (starting in the milk ducts) and lobular carcinoma (starting in the milk-producing glands). 

Grade describes how abnormal the cancer cells look under a microscope and how quickly they appear to be growing. This can provide important information about how aggressive the cancer may be and how the cancer will respond to different treatments. There are three grade classifications:  

• Grade 1 (Low): Cells look relatively normal and are growing slowly 

• Grade 2 (Intermediate): Cells look somewhat abnormal and are growing at a moderate rate. 

• Grade 3 (High): Cells look very abnormal and are growing quickly.  

Stage describes how advanced the cancer is, including the size of the main tumor and whether it’s spread to nearby lymph nodes or other parts of the body. Doctors use information from the biopsy along with imaging, surgery, and other tests to determine the cancer’s stage. Stages range from 0 to IV (4): 

• Stage 0: The cancer has non-invasive cells that have stayed in one place. 

• Stages I to III: The tumors are either localized or have spread to nearby lymph nodes. 

• Stage IV: This cancer is metastatic, meaning it has spread to other distant body parts 

When will I get my biopsy results? 

Waiting for biopsy results can be one of the hardest parts of the process, but it’s important for pathologists to take the time they need to get the most accurate results for your care team. The lab at Woman’s works hard to get the results back to you via MyChart within 24 to 48 hours. However, the exact timing can vary depending on the type of biopsy and what the pathologist sees under the microscope. 

For example, if a breast biopsy is collected on a Monday morning, the tissue may arrive in the pathology lab early that afternoon. It’s processed overnight and is usually ready for the pathologist to examine Tuesday morning. If the cells are benign, the pathologist often completes the diagnosis that day.  

If the cells are cancerous, it might take another day or two to run additional tests to gain more information about the tumor. To ensure your care team receives the most accurate information possible, at least two pathologists will review the case and agree on a diagnosis.  

From biopsy to treatment 

Although you may never meet the pathologist who examines your biopsy, their work plays an important role in understanding your diagnosis and helping your care team plan what comes next. From carefully preparing the tissue to examining it under a microscope and performing additional tests when needed, each step is designed to provide the most accurate information possible.