Understanding Your Prostate Pathology Report
by Dr. C.H. Weaver M.D. 5/1/2015, updated 9/12/2018
What is a pathology test & report?
When your prostate was biopsied, the samples taken were studied under the microscope by a specialized doctor called a pathologist. A pathologist is a physician specializing in the diagnosis of disease based on examination of tissues and fluids removed from the body. Pathology tests involve evaluation of small samples of cells under a microscope to determine whether they are cancerous by identifying structural abnormalities. The pathologist sends your doctor a report that gives a diagnosis for each sample taken. Information in this report is used to help determine treatment.
The Pathology Report
Once a tissue sample is obtained, the pathologist will examine the tissue sample under the microscope in order to determine if it contains normal, pre-cancerous or cancerous cells. The pathologist then writes a pathology report summarizing his or her findings.
The pathology report is a critical component of the diagnostic process. The primary doctor will use this report in conjunction with other relevant test results to make a final diagnosis and develop a treatment strategy.
After any biopsy or excision, you should request a copy of the pathology report for your records so that you have documentation of your pathologic diagnosis. In addition, it is helpful to have a copy of the pathology report to refer to when you are researching your disease.
By having a basic understanding of what the pathologist is looking for and the structure of the report, you may better understand your pathology report. Having a copy of your pathology report for your personal records is highly recommended. Your primary doctor should be able to address specific questions you have about your pathology report.
Understanding your Pathology Report
Although pathology reports are written by physicians for physicians, you may be able to decipher some of the medical jargon provided by the report. The structure and information provided in your pathology report may vary, and the following sections are usually included; the most important of which is the Gleason score.
Demographics: This section includes the patient’s name and date of procedure. You should check that this information is correct to ensure that you have the correct pathology report.
Specimen: The specimen section describes the origin of the tissue sample(s).
Clinical History: The clinical history section provides a brief description of the patient’s medical history relevant to the tissue sample that the pathologist is examining.
Clinical Diagnosis (Pre-Operative Diagnosis): The clinical diagnosis describes what the doctors are expecting before the pathologic diagnosis.
Procedure: The procedure describes how the tissue sample was removed.
Gross Description (Macroscopic): The gross description refers to the pathologist’s observations of the tissue sample using the naked eye. It may include size, weight, color or other distinguishing features of the tissue sample. If there is more than one sample, this section may designate a letter or number system to distinguish each sample.
Microscopic Description: In the microscopic description, the pathologist describes how the cells of the tissue sample appear under a microscope. Specific attributes that the pathologist may look for and describe may include cell structure, tumor margins, vascular invasion, depth of invasion and pathologic stage.
The results from a prostate biopsy include the Gleason score. On the simplest level, this scoring system assigns a number from 6 to 10 to describe how abnormal the cells appear under a microscope. A score of 6 means the cancer cells still look very much like normal cells and pose little danger of spreading quickly. A score of 8 to 10 indicates that the cancer cells have very few features of a normal cell and are likely to be aggressive. Understanding the Gleason score.
Cell Structure: Using a microscope, the pathologist examines the cell structure and microscopic attributes of the tissue sample and assigns a histologic grade to the tumor. The histologic grade helps the pathologist identify the type of tumor. The grade may be described numerically with the Scarff-Bloom-Richardson system (1-3) or as well-differentiated, moderately-differentiated or poorly differentiated.
* Grade 1 or well-differentiated: Cells appear normal and are not growing rapidly.
* Grade 2 or moderately-differentiated: Cells appear slightly different than normal.
* Grade 3 or poorly differentiated: Cells appear abnormal and tend to grow and spread more aggressively.
Tumor Margins: If cancerous cells are present at the edges of the sample tissue, then the margins are described as “positive” or “involved.” If cancerous cells are not present at the edges of the tissue, then the margins are described as “clear,” “negative” or “not involved.”
Vascular Invasion: Pathologists will describe whether or not blood vessels are present within the tumor.
Depth of Invasion: The depth of invasion may not be applicable to all tumors, but is used to describe invasion of the tumor.
Pathologic Stage: The clinical stage is determined from the pathologic stage as well as other diagnostic tests such as X-rays. The pathologic stage, designated with a “p,” describes the extent of the tumor as determined from the pathology report only. The staging system most often used by pathologists is based on the American Joint Commission on Cancer’s (AJCC) TNM (tumor, node invasion, metastasis) system.
What does it mean if the biopsy mentions that there is “perineural invasion”?
“Perineural invasion” means that cancer cells were seen surrounding or tracking along a nerve fiber within the prostate. When this is found on a biopsy, it means that there is a slightly higher chance that the cancer has spread along the nerves outside the prostate. Perineural invasion doesn’t necessarily mean that the cancer has spread outside the prostate. Finding perineural invasion may affect treatment, so if your pathology report mentions perineural invasion make sure you discuss it with your doctor.
What does it mean if, in addition to cancer, the biopsy report also says “high-grade prostatic intraepithelial neoplasia” or “high-grade PIN”?
“High-grade prostatic intraepithelial neoplasia” (or “high-grade PIN”) is a pre-cancer of the prostate. It has no importance whatsoever in someone who already has been diagnosed with cancer. In this case, the word “high-grade” refers to prostatic intraepithelial neoplasia and not the cancer, so it has nothing to do with the Gleason score or how aggressive the cancer is.
How do pathologists measure the amount of cancer in the core?
There are multiple techniques used to quantify the amount of cancer found on needle biopsy. The most common are: (a) number of positive cores, (b) total millimeters of cancer amongst all cores, (c) percentage of each core occupied by cancer, and (d) total percent of cancer in the entire specimen. All of these different methods of measuring cancer volume on needle biopsy are tightly related with each other, such that it is difficult to demonstrate the superiority of one technique of measuring over the other. In general, a report which has the number of positive cores along with one of the other measurements is sufficient.
Other terms on the biopsy report
Atrophy means shrinkage of prostate tissue (when it is seen under the microscope). When it affects the entire prostate gland it is called diffuse atrophy. This is most often caused by hormones or radiation therapy to the prostate. When atrophy only affects certain areas of the prostate, it is called focal atrophy. Focal atrophy can sometimes look like prostate cancer under the microscope.
Adenocarcinoma is the type of cancer that typically develops in the prostate gland
Atypical adenomatous hyperplasia or Adenosis is a benign condition that can sometimes be seen on a prostate biopsy.
Seminal vesicles are glands that lie just behind the prostate which are occasionally sampled during a biopsy.
Acute inflammation (acute prostatitis) or chronic inflammation (chronic prostatitis)?
Inflammation of the prostate is called prostatitis. Most cases of prostatitis reported on biopsy are not caused by infection and do not need to be treated. In some cases, inflammation may increase your PSA level, but it is not linked to prostate cancer. The finding of prostatitis on a biopsy of someone with prostate cancer does not affect their prognosis or the way the cancer is treated.
Special Tests or Markers: Depending on the tissue sample, the pathologist may conduct tests to further determine whether or not specific proteins or genes are present, as well as how fast cells are growing.
Diagnosis (Summary): The final diagnosis is the section where the pathologist compiles the information from the entire pathology report into a concise pathologic diagnosis. It includes the tumor type and cell of origin.
Pathologist Signature: The report is signed by the pathologist responsible for its contents.