What’s Included in Your Breast Cancer Pathology Report? And What Does It Mean?

Soon after a breast biopsy, you might see a pathology report pop up in your online medical record. But if you open it up and don’t know what exactly you’re looking at, you’re not alone.

That’s because breast cancer pathology reports are written by doctors, for doctors. The language is technical, and the findings are often nuanced.

“Most of these reports are designed for physicians to communicate with each other,” says breast medical oncologist Azka Ali, MD. “They’re not necessarily written in a patient-friendly way.”

The report contains important information about your cancer that will influence your team’s care recommendations.

Here’s a closer look at what you may find inside your breast cancer pathology report — and why it’s important to lean on your healthcare team to help make sense of it all.

Parts of the report

A breast cancer pathology report is a detailed document that describes what pathologists found when they examined your biopsy under a microscope. 

The exact format can vary. But in general, here’s what you can expect to see.

Specimen details

The report often begins with basic information about the tissue sample that was tested. This section describes things like:

• Where the biopsy came from, such as your right or left breast and the specific location
• The type of biopsy performed, such as a core needle biopsy, ultrasound-guided biopsy or a surgical tissue specimen, like lumpectomy or mastectomy 
• Information on lymph node tissue if it was sampled
• Technical details about the sample, including how it was collected and processed

These details help doctors confirm exactly what tissue was examined and how.

Tumor type

One of the most important parts of the report is the pathologist’s interpretation, which describes what the cancer looks like under the microscope.

“The pathology report won’t just say ‘breast cancer,’” Dr. Ali notes. “It will have descriptions that describe what type of cancer it looks like.”

The tumor type includes where in your breast the cancer originated: 

• Ductal means it begins in the milk ducts.
• Lobular means it begins in the milk-producing glands (lobules).
• Mixed means it shows characteristics of more than one breast cancer type, such as both ductal and lobular features.

It also describes whether the cancer has spread beyond its original site:

• In situ means the abnormal cells remain contained within the ducts or lobules.
• Invasive means the cancer has spread into surrounding breast tissue.

Tumor size and number of tumors

The pathology report may include additional details about the tumor itself, such as:

• Tumor size
• How many areas of cancer are present (sometimes called “foci”)
• Measurements of each tumor area

“When the whole tumor is removed, the report will describe how big the tumor measured and how many sites of cancer were present,” Dr. Ali explains.

These measurements help doctors understand how extensive the cancer is.

Tumor grade

You may also see a grade listed in your pathology report.

“Grade is basically how ‘funky’ the cancer cells look to the pathologist,” Dr. Ali says.

Breast cancers are typically graded on a scale of 1 to 3:

• Grade 1: Cells look more like normal cells and tend to grow more slowly.
• Grade 2: Cells appear moderately different from normal.
• Grade 3: Cells look very abnormal and may grow more quickly.

Hormone receptor status (ER and PR)

Your pathology report will usually include information about hormone receptors — meaning whether or not the cancer cells use hormones to grow.

The report will note whether the sample contains estrogen receptors (ER-positive or ER-negative) and progesterone receptors (PR-positive or PR-negative).

These markers are important because they help determine which treatments are most likely your team will recommend.

HER2 status

Another key marker for breast cancer is a protein called HER2. It can affect how breast cancer grows.

You may see your HER2 status (HER2-positive or HER-2 negative) noted on the pathology report. But not always.

“The HER2 test sometimes requires confirmation,” Dr. Ali explains. “If the first test is unclear, the pathologist may run another test to determine whether the cancer is HER2 positive or negative.”

Typically, you won’t need to undergo another procedure for this testing. The sample that was already taken just needs to be re-analyzed. This may take some additional time.

Additional comments

Some pathology reports also include a diagnostic comment or addendum. This section may explain:

• How the pathologist reached the diagnosis
• Whether additional stains or tests were performed
• Whether more testing is still underway

These notes help other physicians gain more information about how the pathologist arrived at their findings.

What about cancer stage?

A cancer stage describes whether and how far cancer has spread (metastasized) in your body. Stages are made up of the size of the tumor, whether (the axillary) the lymph nodes are involved or whether the cancer has spread away from the breast or axilla.

The stage is determined based on your biopsy or surgery, as well as other information and test results. So, you won’t always see it on your pathology report. Sometimes, on a surgical report, you may see information about the size of the lymph nodes, depending on the type of surgery you had.

“Because full staging usually requires imaging tests and other clinical information, it’s usually determined after your care team reviews multiple pieces of data, not just the pathology findings,” Dr. Ali notes.

Why it’s important to review your pathology report with your doctor

Seeing a pathology report in your patient portal can be overwhelming and scary. And if your gut instinct is to start searching the web or dropping the report into an AI tool to analyze it, again, know you’re not the only one.

But Dr. Ali encourages you to remember that you don’t need to figure it out alone: “You don’t have to be your own doctor,” she says. “We’re here to help with that.”

What’s more, the interpretations you get from your DIY search may be different from your team’s analysis. That’s because breast cancer is highly individualized.

Your team will take more into account than what’s on that report to better understand your cancer and guide their recommendations. For example, they’ll consider imaging, your health history and treatment goals.

So, it’s important not to jump to conclusions, but instead, to meet with your team to review the findings together. During that conversation, your doctors can help you understand:

• What the report says about your cancer
• Whether additional testing is needed
• What next steps they recommend

And perhaps most importantly, they can help turn doctor-speak into an actionable plan that helps you face cancer. Together.