Prostate Cancer: Understanding Your Biopsy Pathology Report

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Prostate cancer is a cancer that starts in the glands of the prostate, a small organ that sits below the bladder and produces part of the fluid in semen. It is one of the most common cancers in men, and most cases are found while the cancer is still confined to the prostate, at a point when it can be treated successfully or, in many cases, safely watched rather than treated right away.

This article explains the pathology report created after a needle biopsy of the prostate. It covers every item your pathologist must report, in roughly the order you will find them, and it applies to all types of prostate cancer. If your prostate has since been removed, the report from that operation is a different document, and you can read about it in Understanding your radical prostatectomy pathology report.

Why your pathology report looks like a checklist

Most pathology reports for prostate cancer include a section that looks like a list of headings, each followed by a short answer. This is called a synoptic report, and it follows a standard checklist published by the College of American Pathologists (CAP) and used by laboratories across North America, Europe, and much of the world. The checklist makes sure that every feature known to affect treatment decisions is reported for every patient, in the same words, no matter which laboratory examined the tissue.

Prostate biopsy reports are organized in a way that no other cancer report is, and this is the single thing most likely to confuse you when you first read yours. A prostate biopsy is not one piece of tissue. It usually consists of 12 to 14 thin cylinders of tissue, called cores, taken from different parts of the gland and sent to the laboratory in separately labeled containers. The pathologist examines each one and reports on it individually.

Because of this, there are two versions of the checklist, and your report may use one or both:

Specimen level — A separate summary for each container that contained cancer. If cancer was found in 5 of your 12 containers, there may be 5 of these summaries, each with its own grade and its own measurement.
Case level — A single summary for the biopsy as a whole, pulling together the findings from every container into one set of answers.

One checklist covers all types of prostate cancer, so your report may list items that do not apply to your situation. When an item does not apply, the report will say something like “not identified,” “not applicable,” or “cannot be determined.” Seeing those phrases does not mean something was missed. It usually means the feature was looked for but wasn’t there.

How is the diagnosis made?

The diagnosis of prostate cancer is made when tissue from the prostate is examined under a microscope by a pathologist. The tissue is obtained by needle biopsy, in which a thin hollow needle is passed into the prostate, and a core of tissue is removed. The needle may be passed through the wall of the rectum (a transrectal biopsy) or through the skin between the scrotum and the anus (a transperineal biopsy). Most men are referred for biopsy because of a raised prostate-specific antigen (PSA) level, an abnormal finding on physical examination, or a suspicious area seen on MRI.

Under the microscope, the pathologist looks for glands that have lost their normal architecture. Normal prostate glands are lined by two layers of cells: an inner layer of secretory cells and an outer layer of basal cells. In cancer, the basal cell layer is absent, the glands become small and crowded, and the cell nuclei enlarge and develop prominent nucleoli. Because a small focus of cancer can be difficult to separate from several harmless conditions that mimic it, the pathologist may perform immunohistochemistry, a test that uses colored stains to show specific proteins in tissue. A common combination uses stains for basal cell proteins such as p63 and high molecular weight cytokeratin, which are lost in cancer, together with AMACR, which is typically present in cancer and absent in normal glands.

After prostate cancer is confirmed, imaging tests are performed to assess whether it has spread beyond the gland. Depending on your PSA level and the grade of the cancer, these may include MRI of the prostate, a bone scan, CT, or a PSMA PET scan. Men with low-grade, low-volume cancer often need no imaging at all. The pathology report describes what was found in the cores that were removed; imaging describes the rest of the prostate and the rest of the body.

The type of biopsy: systematic, targeted, or both

The case level summary of a prostate cancer biopsy report begins by describing how the biopsy was performed. The answer explains why the cores are labeled the way they are.

Systematic biopsy — Cores are taken in a standard pattern that samples the whole gland, whether or not imaging shows anything abnormal. This is the traditional approach and typically produces 12 to 14 cores.
Targeted biopsy — Cores are aimed at a specific area that looked suspicious on MRI, usually by fusing the MRI images with live ultrasound during the procedure. These are labeled separately, often as “MRI-guided” or with a target number.
Both — Many men now have a systematic biopsy and a targeted biopsy at the same sitting. This is the most informative combination, because each finds some cancers the other misses.

Where the cancer was found

Your prostate cancer biopsy report lists the location of every container that contained cancer. Locations are named by side and by level within the gland, so a report might list right base, left mid, or left apex lateral. The base is the top of the prostate near the bladder, the apex is the bottom near the urethra and the muscles that control urination, and the mid is between them. The transition zone is the inner part of the gland that surrounds the urethra and enlarges with age in benign prostatic hyperplasia. Targeted cores are labeled individually.

These locations matter for what comes next. They tell your surgeon or radiation oncologist which parts of the gland are involved, whether the cancer is on one side or both, and whether it sits near structures that affect surgical planning, such as the nerves responsible for erections or the sphincter muscle at the apex. If you are considering focal treatment of part of the gland rather than the whole prostate, this map is what that decision is built on.

Types of prostate cancer (histologic type)

Histologic type describes what the prostate cancer looks like under the microscope. Almost all prostate cancers are one type, and the checklist lists the others because they exist and must be named when they occur, not because they are common.

Acinar adenocarcinoma

Acinar adenocarcinoma, described on reports as conventional or usual type, accounts for more than 95 out of every 100 prostate cancers. If your report does not name a type at all, or simply says adenocarcinoma, this is what you have. It arises from the cells that line the small glands of the prostate, called acini, and it grows as crowded small glands that infiltrate between the normal structures of the gland. Nearly everything else on your report, including the grade, the measurements, and the treatment options that follow from them, was developed for and validated on this type.

Acinar adenocarcinoma sometimes shows an unusual appearance that the pathologist will name. These are patterns within the same cancer rather than separate diseases, and none of them changes the basic approach to treatment:

Signet ring-like cell pattern — The cells contain a clear space that pushes the nucleus to one side, giving them the look of a ring with a stone.
Pleomorphic giant cell pattern — The cells are large and vary greatly in size and shape.
Sarcomatoid pattern — The cells become spindle-shaped and resemble the cells of a soft tissue tumor.
Prostatic intraepithelial neoplasia-like pattern — The cancer glands resemble a noncancerous change called high-grade PIN, which makes the diagnosis more difficult to make.

Other types of prostate cancer

Types other than acinar adenocarcinoma make up well under 5 in every 100 prostate cancers combined. They are listed on the report because several are treated differently.

Ductal adenocarcinoma — Grows as tall columnar cells forming papillary fronds and larger glands. It tends to be found at a more advanced stage, may produce less PSA than acinar adenocarcinoma, and is generally treated as higher-risk disease.
Isolated intraductal carcinoma — Cancer cells filling and expanding existing prostate ducts, with the basal cell layer still present. Rarely the only finding on a biopsy. It is discussed in its own section below.
Adenocarcinoma with neuroendocrine differentiation — An otherwise ordinary adenocarcinoma containing scattered hormone-producing cells. Usually treated as adenocarcinoma.
Small cell neuroendocrine carcinoma and large cell neuroendocrine carcinoma — Fast-growing cancers made of neuroendocrine cells. They often produce little or no PSA, do not respond to hormone-blocking therapy, and are treated with chemotherapy instead, so naming them changes the treatment plan entirely. They sometimes emerge in men treated with long-term hormone therapy for ordinary prostate cancer.
Well-differentiated neuroendocrine tumor — A rare, slower-growing neuroendocrine tumor of the prostate.
Squamous cell carcinoma and adenosquamous carcinoma — Rare cancers made partly or entirely of flat, scale-like cells. They do not respond to hormone-blocking therapy.
Basal cell carcinoma, also called adenoid cystic carcinoma — A rare tumor arising from the basal cell layer rather than the secretory cells. Most behave in a limited way, though some spread locally.

Histologic grade: Gleason score and Grade Group

Grade is the most important number on a prostate cancer biopsy report. It describes how much the cancer glands have departed from the prostate’s normal architecture, and it predicts behavior better than any other single feature. Prostate cancer uses its own grading system, which works differently from the grading systems used for other cancers.

Gleason patterns

The pathologist assigns a Gleason pattern to the areas of cancer based on how the glands are arranged. Only three patterns are in current use:

Pattern 3 — The cancer still forms separate, well-shaped glands. This is the least concerning pattern.
Pattern 4 — The glands are poorly formed, fused together, or arranged in sheets with punched-out holes.
Pattern 5 — The cancer has largely given up making glands, growing instead as sheets, cords, or single cells, sometimes with dead tissue in the center.

Patterns 1 and 2 were part of the original system but are no longer assigned, which is why the lowest score you can receive today is 6 rather than 2.

Gleason score

The Gleason score adds two pattern numbers together. On a biopsy, the first number is the pattern that makes up most of the cancer, and the second is the worst remaining pattern present. If only one pattern is present, it is doubled. This is why the score is written as a sum: 3+4=7 means mostly pattern 3 with some pattern 4, and 4+3=7 means mostly pattern 4 with some pattern 3. Both add to 7, but they are not the same cancer, and 4+3 carries the higher risk.

Grade Group

Because the Gleason score no longer uses the bottom half of its own scale, the scores are also reported as a Grade Group from 1 to 5. This system is now the primary way prostate cancer grade is described, and your report should give both.

Grade Group 1 (Gleason score 6, or 3+3) — Only well-formed glands. This is the lowest grade of prostate cancer that can be diagnosed. Cancers in this group very rarely spread, and most men with Grade Group 1 disease are offered active surveillance rather than immediate treatment.
Grade Group 2 (Gleason score 7, or 3+4) — Mostly well-formed glands with a smaller amount of pattern 4.
Grade Group 3 (Gleason score 7, or 4+3) — Mostly pattern 4 with a smaller amount of well-formed glands.
Grade Group 4 (Gleason score 8, whether 4+4, 3+5, or 5+3) — Poorly formed glands throughout, or a combination that reaches 8.
Grade Group 5 (Gleason score 9 or 10) — Little or no gland formation. The highest grade, and the group most likely to spread.

If you take away one thing from your report, it should be this: a Gleason score of 6 is not a 6 out of 10. It is the bottom of a scale that runs from 6 to 10, and Grade Group 1 is the least concerning result that can be reported. Many men who see the number 6 assume their cancer is midway to the worst possible, and it is not.

Percentage of pattern 4

When the Gleason score is 7, your prostate cancer report should also give the proportion of the cancer made up of pattern 4, usually as a range such as 5 percent or less, 6 to 10 percent, or greater than 40 percent. This matters because Gleason score 7 covers a wide span of risk. A cancer that is 5 percent pattern 4 behaves very differently from one that is 40 percent pattern 4, and men with a small amount of pattern 4 may still be candidates for active surveillance. When the score is 8 or higher, the percentages of pattern 4 and pattern 5 may also be given.

When no grade is given

Your report may state that the grade is not applicable or cannot be assessed. There are three common reasons, and none of them is an error:

Tumor microfocus — The amount of cancer in that core is too small to grade reliably. Rather than assign a number that might be wrong and could change your treatment, the pathologist reports the finding without a grade.
Cancer seen only around a nerve — When the only cancer in a core surrounds a nerve, it is not graded.
Previous treatment — Hormone-blocking therapy and radiation change the appearance of prostate cancer cells so much that the Gleason system no longer applies.

Cribriform glands

Cribriform glands are sheets of cancer cells punched through with round holes, like a sieve. They are one of the several architectures that count as Gleason pattern 4, and your prostate cancer report states separately whether they are present when the Gleason score is 7 or 8.

They are singled out because among the pattern 4 architectures, cribriform growth is the one most consistently linked to a higher chance of the cancer spreading and recurring after treatment. Two cancers can both be Grade Group 2, and the one with cribriform glands carries the higher risk. In practice, the presence of cribriform glands often moves a man away from active surveillance and toward treatment, so this single line can change what is recommended to you.

Intraductal carcinoma

Intraductal carcinoma, abbreviated IDC, means cancer cells are filling and expanding the existing ducts of the prostate while the normal basal cell layer around those ducts is still in place. On a biopsy, it is almost always found alongside ordinary invasive cancer, and finding it on its own is rare.

Intraductal carcinoma is reported because it is an independent warning sign. It is strongly associated with high-grade, high-volume cancer elsewhere in the gland, even when the cores themselves show only a small amount of cancer, and it is associated with a higher risk of recurrence after treatment. It is also more common in men who carry an inherited BRCA2 gene change, so its presence may prompt a referral for genetic testing.

Your report may also state whether the intraductal carcinoma was incorporated into the grade. Pathology organizations disagree on this point: one recommends including it when assigning the Gleason score, the other recommends excluding it. Neither approach is wrong, and the report states which was used so that your treating physician can interpret the grade correctly.

Grade for the whole case: highest, composite, and global

When cancer is found in more than one container, and the containers have different grades, a prostate cancer biopsy report may give more than one overall grade for the case. Seeing several different Grade Groups on a single report is expected, not a contradiction.

Highest grade — The grade of the single worst container. This is the number most often used to guide treatment because the most dangerous part of the cancer drives the outcome.
Composite grade — A combined grade calculated for cores that sit next to one another and appear to be sampling the same tumor. It avoids diluting a significant tumor by averaging it with unrelated low-grade cancer elsewhere in the gland, and it corresponds most closely to what is found if the prostate is later removed.
Global grade — A combined grade calculated across all positive cores regardless of where they sit.
Targeted biopsy grade — The grade of an MRI-targeted lesion, reported separately for each target. A grade may also be reported combining the systematic and targeted cores.

Tumor quantitation: how much cancer was found

Along with grade, the amount of prostate cancer in the biopsy is what determines whether treatment is recommended now or the cancer can be monitored. Your report quantifies it in several ways.

Total number of cores and number of positive cores — For example, cancer in 3 of 12 cores. This ratio gives a rough sense of how widely the cancer is distributed through the gland.
Percentage of the core involved — How much of each positive core is made up of cancer, given as a range such as 1 to 5 percent or greater than 90 percent. The case-level summary gives the greatest percentage found in any single core, since that number is the one used in most treatment guidelines.
Length of cancer in millimeters — A direct measurement of the cancer along the core, reported alongside or instead of the percentage.
Measurement technique — Whether the cancer occupied one continuous stretch of the core, or several separate spots that were measured as a single span, or several separate spots that were measured and added together.

That last item sounds technical but has real consequences. If a core is 20 millimeters long and has cancer at each end with normal tissue in between, the involvement can be described as 100 percent if measured end to end, or as 10 percent if only the cancer itself is added up. Both descriptions are honest, and the difference can determine whether you meet the criteria for active surveillance. Many programs exclude men with any core more than 50 percent involved. If your report gives both numbers, or if the number looks surprisingly high, ask about it directly.

Periprostatic fat invasion

Periprostatic fat is the fatty tissue that surrounds the outside of the prostate. There is essentially no fat inside the gland itself, so when a needle biopsy contains fat with cancer growing in it, the cancer has reached beyond the edge of the prostate. This is called extraprostatic extension, and finding it on a biopsy means the cancer is at least stage T3a.

This finding is uncommon on biopsy because the needle targets the gland rather than its outer surface. When it does appear, it is usually accompanied by high-grade cancer, and it generally moves a man into a higher risk category and away from surveillance or from surgery alone.

Seminal vesicle and ejaculatory duct invasion

The seminal vesicles are two small glands that sit behind and above the prostate and contribute fluid to semen. Cancer growing into the muscular wall of a seminal vesicle indicates stage T3b disease, which affects treatment planning considerably.

There is an important qualification, and your report may include a comment about it. Only the portion of the seminal vesicle lying outside the prostate counts for staging. Seminal vesicle tissue is sometimes picked up unintentionally during a biopsy, and that tissue usually comes from the part running through the prostate, where involvement by cancer does not mean stage T3b. It can also be difficult to tell seminal vesicle from ejaculatory duct under the microscope. When the pathologist cannot be certain, the report says so, specifically to prevent the cancer from being staged higher than it should be.

Lymphovascular invasion

Lymphovascular invasion means cancer cells were seen inside small blood vessels or lymphatic channels. These vessels are one of the routes by which prostate cancer reaches lymph nodes and bones, so their involvement indicates that cells have gained access to that route. It does not mean the cancer has spread.

Lymphovascular invasion is uncommon in needle biopsies, and most reports state that it was not identified. When present, it is associated with higher-grade disease and a higher risk of recurrence.

Perineural invasion

Perineural invasion means cancer cells were seen surrounding or tracking along a nerve. The prostate is densely supplied with nerves, and cancer commonly spreads along the outside of them, so this is one of the more frequent findings on a prostate biopsy report.

Its significance is genuinely uncertain, which matters because the phrase sounds alarming. Some studies have found it predicts that cancer will be found outside the gland at surgery; others have found it adds nothing once grade and volume are accounted for. Guidelines do not treat it as a reason to change course on its own, though some surveillance programs take it into account, and it may influence whether a surgeon attempts to spare the nerves near the tumor.

Treatment effect

This item applies only if you received hormone-blocking therapy or radiation before the biopsy. Both substantially change the appearance of prostate cancer cells: the cells shrink, develop clear or foamy cytoplasm, and lose the architecture grading depends on. The report notes whether radiation, hormonal therapy, or another treatment effect is present.

The main consequence is that treated cancer is not assigned a Gleason score or Grade Group, because the system was never designed for it and a grade assigned to treated tissue would be misleading. If a new area of cancer without treatment effect is present, that area can still be graded, and the report will say so.

Other findings in the biopsy

The pathologist examines all of the tissue in every core, not only the cancer, and reports other abnormalities found along the way. None of these is prostate cancer, but two of them can change what happens next.

High-grade prostatic intraepithelial neoplasia (PIN) — Abnormal cells lining otherwise normal ducts and glands, with the basal cell layer intact. It is considered a precursor to cancer. When found alone, it was once regarded as a strong reason to repeat the biopsy; that risk is now known to be much lower, and repeat biopsy is generally considered only when it is present at several sites. When cancer is already present, high-grade PIN adds nothing and is often not reported at all.
Atypical intraductal proliferation (AIP) — Cells growing inside ducts that are more abnormal than high-grade PIN but fall short of intraductal carcinoma. It matters because it may represent the edge of an intraductal carcinoma that the needle did not fully sample, and it is often a reason to biopsy again or look more closely with imaging.
Atypical small acinar proliferation (ASAP) — A small group of glands that are suspicious for cancer but too few or too distorted for a firm diagnosis. It is not a diagnosis of cancer. It is a statement that the pathologist could not be certain, and it usually leads to a repeat biopsy, because cancer is found in a substantial proportion of men on the second attempt.
Inflammation — Immune cells in the prostate tissue, sometimes called prostatitis. It is common, usually causes no symptoms, and is not a precursor to cancer. It is noted on the report because inflammation can raise PSA levels and may explain a result that prompted the biopsy.
Benign prostatic hyperplasia — Enlargement of the normal prostate gland and surrounding tissue, present in most men over 50. It is not cancer and does not become cancer, though it also raises PSA.

Why there is no stage on your biopsy report

Most cancer pathology reports end with a pathologic stage, written as pT and pN. A prostate biopsy report does not, and its absence is not an omission. Stage describes how far a cancer has spread, and a needle biopsy samples only a few thin cylinders from inside the gland. It cannot show how much of the prostate is involved or whether the cancer has reached the lymph nodes, so a pathologic stage cannot be assigned from it. The exceptions are the two findings described above, periprostatic fat invasion and seminal vesicle invasion, which establish a minimum stage when they appear.

Instead, your treating physician assigns a clinical stage based on physical examination, imaging, and PSA. That clinical stage is then combined with your Grade Group and your PSA level to place the cancer in a risk group, with names such as low risk, favorable intermediate risk, unfavorable intermediate risk, and high risk. Treatment recommendations are based on the risk group, not the pathology report alone. This is also why two men with the same Grade Group can be given very different advice.

Biomarker and molecular testing

Unlike breast and lung cancer reports, a prostate cancer biopsy report does not routinely include biomarker results, and the checklist has no section for them. Several tests may still be ordered on your biopsy tissue or your blood, and the results usually arrive separately.

Genomic classifiers — Tests such as Decipher, Prolaris, and the Oncotype DX Genomic Prostate Score measure the activity of a panel of genes in the tumor tissue to refine the estimate of how the cancer is likely to behave. They are used most often when the choice between surveillance and treatment, or the decision about adding radiation or hormone therapy, is finely balanced.
Inherited gene testing — Changes in BRCA2 and BRCA1, ATM, and the mismatch repair genes can be inherited and raise the risk of prostate cancer and other cancers in a family. Testing requires a blood or saliva sample rather than the tumor tissue. It is generally offered to men with high-risk or metastatic disease, with intraductal carcinoma, or with a significant family history, and it can affect both your treatment options and cancer screening for your relatives.
Mismatch repair and microsatellite instability — Tested on the tumor tissue in advanced disease. A tumor with loss of mismatch repair may respond to immunotherapy.
Androgen receptor testing — Relevant in advanced prostate cancer that has stopped responding to hormone-blocking therapy, where changes in the androgen receptor help explain resistance and guide the choice of next treatment.

You can read more about these tests in the Biomarkers and Genetic Testing section of this website.

What is the prognosis?

Prognosis is the expected course of a disease. For prostate cancer, the outlook is better than for almost any other cancer. Across all stages combined, roughly 97 out of every 100 men diagnosed with prostate cancer are alive five years later. When the cancer is confined to the prostate or has spread only to nearby tissue, survival at five years is close to 100 percent, and most of these men die of something else entirely. When the cancer has spread to distant sites such as bone, five-year survival is closer to 37 out of 100, though this figure has been improving as new treatments arrive.

These figures describe large groups of men and cannot predict what will happen to any one person. Within prostate cancer, the range of behavior is wide, and the findings on your report are what place you within it:

Grade Group — The strongest predictor. Grade Group 1 cancers rarely spread; Grade Group 5 cancers require the most intensive treatment.
Amount of cancer — The number of positive cores and how much of each core is involved.
Cribriform glands and intraductal carcinoma — Both raise risk beyond what the Grade Group alone indicates.
PSA level — Measured in blood rather than reported by the pathologist, and combined with grade and stage to determine your risk group.
Extension beyond the gland — Periprostatic fat or seminal vesicle involvement moves the cancer into a higher stage and a higher risk group.

What happens after this diagnosis?

The pathology report from a prostate biopsy is the document your treatment team uses to decide whether the cancer needs to be treated now, and if so, how. A urologist usually coordinates care, often with a radiation oncologist and a medical oncologist.

The findings on your report shape several decisions:

Active surveillance — Monitoring the cancer with regular PSA tests, examinations, MRI, and repeat biopsies, and treating only if it progresses. This is the standard recommendation for most men with Grade Group 1 disease and for selected men with favorable Grade Group 2 disease, and it avoids the side effects of treatment for cancers unlikely ever to cause harm.
Surgery — Removal of the prostate, called radical prostatectomy. The pathology report from that operation gives the definitive grade and stage, which sometimes differ from the biopsy.
Radiation therapy — Delivered from outside the body or by placing radioactive seeds in the gland, sometimes combined with hormone-blocking therapy.
Hormone-blocking therapy — Used with radiation in intermediate- and high-risk disease, and as a main treatment when cancer has spread.
Imaging — Bone scan, CT, or PSMA PET, depending on your grade and PSA.
Genetic assessment — Considered based on the grade, the presence of intraductal carcinoma, and your family history.

If any part of your report is unclear, your treating physician can request the full report from the laboratory and go through it with you, and a second opinion on the pathology can be arranged if you would like one. Second review of prostate biopsies is common and is standard practice before starting active surveillance at many centers.

Questions to ask your doctor

What is my Grade Group, and what Gleason score does it correspond to?
Is my Gleason score 3+4 or 4+3, and what difference does that make for me?
If my score is 7, what percentage of the cancer is pattern 4?
How many cores were taken, and how many contained cancer?
What was the greatest percentage of any single core involved by cancer?
Were cribriform glands found in my biopsy?
Was intraductal carcinoma found, and was it included in my grade?
Which parts of my prostate were involved, and was cancer found on both sides?
Was perineural invasion found, and does it change anything in my case?
Does my report mention periprostatic fat or seminal vesicle involvement?
What risk group am I in once my PSA and clinical stage are taken into account?
Am I a candidate for active surveillance, and what would that involve?
Would a genomic test such as Decipher or Prolaris help decide my treatment?
Should I be referred for genetic testing based on my diagnosis and family history?