Making Sense of Your Colon Pathology Report

A pathology report is provided after a doctor, called a pathologist, reviews the biopsied colon tissue to determine if cancer is present. More than likely, your doctor will review the results with you. However, the medical terms can be difficult to understand. Learn more about what you will likely find in the report and what it means.

The Purpose of a Biopsy

Your doctor recommended a colon biopsy, or a biopsy of a polyp removed during a colonoscopy, because some abnormal cells were found. This doesn’t always mean you have cancer. A pathologist will carefully examine the cells to see if cancer is present. If it is cancer, the report will include more details, like the tumor's type and location, how aggressive it is, and the presence of microsatellite instability (MSI), an abnormality in cancer cells.

Terms Frequently Used in Colon Pathology Reports

Colon pathology reports contain a lot of medical jargon that is more familiar to doctors than patients. The text below contains common medical terms found in colon pathology reports:

• Cecum: The start of the colon, where the small and large intestines meet.

• Ascending colon, transverse colon, and descending colon: The colon segments after the cecum.

• Sigmoid colon: The end part of the colon that connects to the rectum.

• Rectum: The area that holds waste until a bowel movement occurs.

• Mucin: A lubricant made in the colon. Some types of colon cancers generate a large amount of mucin, leading to them being called mucinous or colloid adenocarcinomas.

• Polyps: Growths in the lining of the colon. If a polyp is tested, a description of its type will be provided.

• Invasive or infiltrating: Terms used to describe cancer that has spread beyond the lining of the colon.

• Dysplasia: Describes changes in cells detected in the colon. The range of cell changes will be described as low grade to high grade based on their abnormal appearance under a microscope.

• Margin: This area around the surgical site needs to be clear of cancer cells. If it is not, additional surgery and/or treatments may be needed.

• Differentiation: refers to the cancer grade and explains how abnormal the cells appear. The three colon cancer grades are well-differentiated (low grade), moderately differentiated (intermediate grade), and poorly differentiated (high grade). Lower grades mean that the cancer cells look more like normal cells and are less likely to spread as quickly.

What Are the Different Types of Colon Polyps?

Many people have a polyp biopsy after a screening test. This is because some polyps are more likely to become cancerous, or the doctor may notice that the polyp looks suspicious.

Colon polyps are classified in several ways. They are either neoplastic (adenoma), meaning they could become cancerous, or non-neoplastic (hyperplastic), meaning they will not. They are also often described by their shape as they appear under a microscope. The structure of these colon polyps can help determine the potential risk of cancer.

Your pathology report might reference some of the following types of colon polyps:

• Adenomatous polyps are the most common type of colon polyp. Based on their growth patterns, they are grouped into villous, tubular, and tubulovillous adenoma subtypes. Adenomatous polyps must be removed since they can eventually develop into colon cancer.

• Serrated polyps have a saw tooth pattern when viewed under the microscope. Types of serrated polyps include traditional serrated adenomas and sessile serrated adenomas (also called sessile serrated polyps), which are flattened and broad.

• Hyperplastic polyps are typically benign and do not need to be removed as they are not cause for concern.

Determining the T in the Stage of Colon Cancer

There are three key factors in staging colon cancer:

• T - The tumor size and extent. Larger tumors and those that have grown into the colon wall or beyond are typically at a later stage.

• N - indicates whether lymph nodes are involved

• M - has the cancer metastasized or spread to other organs beyond the colon?

More than likely the doctor already knew the approximate size based on the images taken to identify where the tumor is located. However, it’s difficult to know how far it’s grown into the colon wall until the biopsy is performed.

The Grade of Colon Cancer is Identified in the Pathology Report

The differentiation of the cells will give the pathologist a sense of how quickly the tumor is growing. This is called the grade of cancer. More differentiated cells mean the cancer cells are rapidly dividing. The higher the grade of colon cancer, the more aggressive the cancer.

Understanding the Genetics of Colorectal Cancer

Most gene mutations in colorectal cancers are not hereditary, meaning they are not passed down from one family member to another. Research suggests that only about 5% of all colorectal cancers are caused by inherited gene mutations, while the remaining 95% are caused by non-genetic mutations acquired during a person's lifetime. While separate biomarker testing will likely be performed on the biopsied tissue, some genetic data can be found in the pathology report.

Understanding MSI, MSH2, MSH6, MLH1, PMS2

Pathology reports sometimes refer to an abnormality called microsatellite instability (MSI) in the cancer cells, detected during testing on your tumor. In this situation, your oncologist will probably suggest further genetic testing to determine if you have tested positive for Lynch Syndrome. Lynch Syndrome is linked to an increased risk of developing colon cancer and other types of cancer. The results of these tests will help determine the most appropriate treatment and its level of aggressiveness.

My Pathology Report Shows Colon Cancer: What Now?

The best way to get the answers you need regarding the next steps for a cancer diagnosis is to speak with an oncologist specializing in colon cancer. The colorectal cancer specialists at Affiliated Oncologists are ready to assist you if you have been diagnosed with colorectal cancer following a colonoscopy and have questions regarding your colon pathology report. Request an appointment to speak with a colon cancer doctor about a diagnosis and options for treatment.

Located in the south suburbs of Chicago, we provide personalized colorectal cancer treatment plans tailored to each patient. We also offer second opinions on previously received treatment recommendations.

Categories: Colorectal Cancer