Understanding Your Pathology Report

Most pathology reports include these sections: 

• Demographic information: Your name, birthdate, medical record number, presumed diagnosis, and the ordering doctor.
• Specimen type: From which part of the colon or rectum the specimen was taken.
• The type of procedure used to take the specimen, such as a biopsy or a specific type of surgery. 
• Gross description: How the tissue appears to the pathologist’s naked eye, including size, weight, and color.
• Microscopic description: A technical description of what the specimen looks like under a microscope. 
• Histologic grade: The pathologist will assign the cells a grade, based on how abnormal they look under a microscope. High-grade cancers (poorly differentiated) tend to grow and spread more quickly than low-grade cancers (well and moderately differentiated). Knowing the grade of the cancer can help predict a person's prognosis (outlook for recovery). 

Colorectal cancer cells are assigned the following grades:

• GX: The tumor grade cannot be identified.
• G1: The cells are more like healthy cells (well differentiated)
• G2: The cells are somewhat like healthy cells (moderately differentiated)
• G3: The cells look less like healthy cells (poorly differentiated)
• G4: The cells barely look like healthy cells (undifferentiated)
• Tumor cell type: The type of cancer cells that are found in the tumor. There are several types of colorectal cancer. Adenocarcinoma is the most common type.
• T stage/Depth of invasion: This indicates the size of the tumor and how far it has invaded (spread) into the colon wall. Cancer that has not invaded the surrounding tissues is called in situ. A cancer that has penetrated the surrounding tissues is called invasive.

T (tumor) stage is classified as:

• Tx: The tumor cannot be measured.
• T0: There is no evidence of a tumor.
• T1s: The cancer cells are found only in superficial tissue (in situ)
• T1, T2, T3, or T4: Describes the size of the tumor based on size and depth of spread to surrounding areas. 
• Vascular, lymphatic, or lymphovascular (angiolymphatic) invasion: When the pathologist examines the specimen and nearby tissue, they determine if the cancer has grown into the small blood vessels and/or lymph vessels of the colon or rectum. If it has, there is a higher chance that it could have spread outside the colon or rectum. This is not the same as cancer cells that are found in the lymph nodes.
• Lymph nodes: Cancer cells can travel through the lymph system to spread to other parts of the body. During colorectal cancer surgery, several lymph nodes are removed to be examined by the pathologist. The pathology report will state the number of lymph nodes that were examined and how many that had cancer cells in them. A lymph node is called “positive” when it contains cancer and “negative” when it does not.
• Margins: During surgery to remove cancer, the surgeon removes the tumor and some surrounding tissue. The pathologist then examines the edges (margins) of the specimen to see if there are any remaining cancer cells. A “positive” or “involved” margin means cancer cells were found in the edges. 
• Diagnosis: In this section, the pathologist gives a definitive diagnosis based on the information above. If cancer has been found, the diagnosis typically includes:
  • Type of cancer
  • Tumor grade
  • Lymph node status
  • Margin status
  • T stage/depth of invasion
  • Stage of cancer