The Role of Pathology

A complete and accurate pathology report is crucial to getting a precise diagnosis and deciding on the best treatment plan for you.

Patients at Memorial Sloan Kettering benefit from the experience and expertise of our ten teams of disease-specific pathologists — doctors who specialize in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. They use state-of-the-art equipment and the most advanced techniques to analyze thousands of tissue samples each year.

The pathologist determines the precise type and severity (stage) of the cancer and may also work with other members of your care team to recommend a treatment strategy that could include observation, surgery, chemotherapy, radiation therapy, or a combination of these approaches.

Communication between my group and the treatment team taking care of the patient is an absolute must.
Meera R. Hameed
Meera R. Hameed Pathologist

Obtaining a Tissue Sample

Doctors will often recommend a biopsy after a physical examination or a diagnostic test has identified a possible cancer. During a biopsy, a doctor removes a small amount of tissue from the area of the body in question so it can be examined by a pathologist.

For most types of cancer, a biopsy is the only way to make a definitive cancer diagnosis. The most common types of biopsy include:

  • incisional biopsy, in which only a sample of tissue is removed
  • excisional biopsy, in which an entire lump or suspicious area is removed
  • needle biopsy, in which a sample of tissue or fluid is removed with a needle

As cancer care becomes more personalized, obtaining a biopsy sample that provides enough material not only for diagnosis but for genetic analysis is critical. Interventional radiology is an approach used at MSK to obtain a tissue sample from areas of the body that may not be easily accessible, such as the liver or lung.

Image-Guided Biopsy

To obtain the tissue sample, an interventional radiologist uses imaging techniques such as CT, ultrasound, PET, or MRI, depending on which technique provides the best visuals of the area, along with minimally invasive tools such as needles.

Learn more about how our doctors use interventional radiology techniques to treat cancer.

After doctors obtain the biopsy, the sample goes to a pathologist who analyzes the appearance of the cells under a microscope and determines whether the tissue that was removed is benign (noncancerous) or malignant (cancerous). If the tissue is cancerous, pathologists run other tests to reveal additional characteristics of the cancer and whether it’s likely to spread to other parts of the body.

The Pathology Report

The pathology report describes the pathologist’s diagnosis based on his or her examination of a tissue sample taken from your tumor, or in the case of blood cancers, a sample taken from one of your lymph nodes or bone marrow. If cancer is diagnosed, the report will provide specific information about the characteristics of the cancer cells, which helps your doctor recommend the best treatment options for you.

The report details the type of cancer involved, whether it’s invasive and able to spread to other parts of the body, and how far the cancer has penetrated into surrounding healthy tissues. It also includes information about:

  • Histologic grade, which compares the size, shape, and other characteristics to those of your healthy cells. For example, a tumor with cells that look more like healthy cells is called low grade or well differentiated, and is often associated with a better prognosis, or chance of recovery.
  • Mitotic rate, which details how often the cancer cells are dividing. Tumors with fewer dividing cells typically are low grade and are more likely to correspond to a better prognosis for the patient.
  • Lymph node status, which documents whether the cancer has spread to nearby lymph nodes — small, bean-shaped glands that help fight infection — or other organs. If the tumor has invaded the blood vessels or lymph vessels that flow into the lymph nodes, there is a greater chance that the cancer has metastasized (spread) to other parts of the body.
  • Stage, or extent of cancer in the body based on the tumor’s size, location, and spread. The pathologic stage, along with the results of other diagnostic tests, helps guide a person’s treatment options.
  • Other test results indicating the presence of hormone receptors or other tumor markers.

Genomic Sequencing

Diagnostic accuracy has improved with the use of newer technologies that can further classify cancers and identify specific genes, proteins, and genetic mutations or alterations that drive tumor growth.

For example, experts at MSK have developed a genome-sequencing test that allows our doctors to quickly find out whether a patient’s tumor carries mutations that could aid in treatment and to match individual patients with available therapies or clinical trials that will most benefit them.

The test, called MSK-IMPACT™, allows for the comprehensive molecular analysis of cells from any type of solid tumor, regardless of where in the body the cancer is thought to have arisen. MSK researchers recently worked with a biotech company to co-develop a similar genomic test to identify genetic alterations in blood cancers.

Results of these types of tests may be listed on your pathology report or made available to you in a separate report.

Pictured: Ross Levine
New Diagnostic Test for Blood Cancers Will Help Doctors Tailor Treatments
A new diagnostic test co-developed by Memorial Sloan Kettering identifies hundreds of genetic alterations in blood cancers, which will guide physicians in treatment decisions.
Learn more