Papillary Urothelial Carcinoma: Understanding Your Pathology Report
Papillary urothelial carcinoma is a type of cancer that starts from the urothelial cells that line the inside of the urinary tract. The word papillary means the tumor grows as finger-like projections that stick out from the lining into the open space inside the bladder. Most papillary urothelial carcinomas start in the bladder, but they can also start in the kidney, the ureters, or the urethra.
Papillary urothelial carcinoma is the most common way bladder cancer first appears. Most of these tumors are found while the cancer cells are still confined to the lining, which is called non-invasive papillary urothelial carcinoma. Less often, the cancer cells have grown below the lining into the wall of the bladder, which is called invasive papillary urothelial carcinoma.
This article explains how papillary urothelial carcinoma is diagnosed and what your pathology report says about the grade, invasion, and stage of the tumor. Most of the article describes tumors removed from the bladder in a procedure called a TURBT.
Who gets papillary urothelial carcinoma?
Papillary urothelial carcinoma of the bladder is mainly a disease of older adults, and the typical age at diagnosis is in the early 70s. It is about four times more common in men than in women. It is uncommon before the age of 40, although low-grade papillary tumors are occasionally found in younger adults.
What causes papillary urothelial carcinoma?
Smoking is the most important cause of papillary urothelial carcinoma, because chemicals from tobacco smoke are filtered into the urine and damage the lining of the bladder. Long-term exposure to certain industrial chemicals, such as aromatic amines once used in dye and rubber manufacturing, also increases risk. Other causes include arsenic in drinking water and earlier treatment with radiation to the pelvis or with the chemotherapy drug cyclophosphamide.
A small number of urothelial carcinomas are linked to an inherited condition called Lynch syndrome. This link is strongest for tumors that start in the kidney or ureter. Stopping smoking lowers the chance of new tumors forming in the bladder after treatment.
What are the symptoms of papillary urothelial carcinoma?
The most common symptom of papillary urothelial carcinoma is painless blood in the urine that may come and go. Because the finger-like projections are fragile, they bleed easily, even when the tumor is small. Some people notice the blood themselves, while in others it is found only on a urine test. Less common symptoms include burning during urination and needing to urinate often or urgently.
How is the diagnosis made?
The diagnosis of papillary urothelial carcinoma usually begins after blood is found in the urine. A doctor may send a urine sample for cytology, a test in which a pathologist looks for cancer cells in the urine. Urine cytology is good at finding high-grade cancer cells, but it often misses low-grade tumors because their cells look so similar to normal cells. Our article on cytology explains this test.
A urologist then looks inside the bladder with a thin camera, a procedure called cystoscopy. A papillary tumor often looks like a small piece of seaweed or a cauliflower floating from the bladder wall. It is removed through the urethra in a procedure called a transurethral resection of bladder tumor, or TURBT. Our article on the TURBT pathology report explains the procedure and what pathologists examine.
Under the microscope, a pathologist sees thin projections called papillae, each with a central stalk of tissue and blood vessels called a fibrovascular core. In papillary urothelial carcinoma, the cells covering these papillae are abnormal. The pathologist uses how abnormal they look to separate this cancer from noncancerous papillary growths, such as a urothelial papilloma.
The pathologist also checks whether the thick muscle layer of the bladder wall, called the muscularis propria, is present in the sample. This matters because a tumor can be shown to have reached the muscle only if the tissue removed included muscle. Your TURBT report will describe the muscle layer in one of these ways:
- Not identified. No muscle was included in the sample, so the pathologist cannot tell whether the cancer has reached it. For a high-grade or invasive tumor, a second TURBT is often done.
- Present, negative for tumor. The sample included muscle, and no cancer cells were seen in it.
- Present, involved by tumor. Cancer cells have grown into the muscle, which means the cancer is muscle-invasive.
- Cannot be determined. The pathologist could not tell with certainty, often because the tissue was damaged during removal.
Muscle is often absent from the sample of a small, low-grade, non-invasive tumor because the urologist doesn’t need to remove it. Imaging, such as a CT scan, is often used to check the kidneys and ureters for other tumors. If the cancer is invasive, scans are also used to look for spread to lymph nodes and other organs.
Histologic grade
Papillary urothelial carcinoma is given a grade based on how different the tumor cells look from normal urothelial cells. Grade is one of the most important findings in your report for a non-invasive tumor. It helps predict how the tumor will behave, and your team uses it to plan treatment and follow-up. There are two grades:
- Low grade. The tumor cells look only slightly different from normal urothelial cells and are arranged in an orderly way. Low-grade tumors often come back in the bladder, but they rarely grow into the muscle or spread. Our article on low-grade papillary urothelial carcinoma describes these tumors in more detail.
- High-grade. The tumor cells look very different from normal urothelial cells and are arranged in a disorderly way. High-grade tumors are more likely to grow into the bladder wall and to spread. Our article on high-grade papillary urothelial carcinoma describes these tumors in more detail.
Some papillary urothelial carcinomas contain both low-grade and high-grade areas. Under the World Health Organization (WHO) classification, 5th edition (2022), the tumor is graded as high grade when the high-grade areas make up 5% or more of the tumor. When they make up less than 5%, your report may say “low grade with less than 5% high-grade component.” These tumors seem to behave more like low-grade tumors, but your team may follow them more closely.
Some reports, especially in Europe, also assign a grade from 1 to 3 using an older 1973 WHO system. This grade is optional, and it is given alongside the low and high grade rather than replacing it. Grade 1 is the most normal-looking and grade 3 the most abnormal.
Non-invasive and invasive papillary urothelial carcinoma
After grade, the most important finding for papillary urothelial carcinoma is whether the cancer cells have grown below the lining into the bladder wall. This process is called invasion. The bladder wall has several layers, and your report will name the deepest layer containing cancer cells.
- Non-invasive papillary carcinoma. The cancer cells are confined to the lining and papillae, and none have grown into the underlying tissue. Your report may also use the term non-invasive. These tumors are staged as pTa.
- Invades the lamina propria. The cancer cells have grown into the lamina propria, the thin layer of connective tissue just below the lining. These tumors are staged as pT1, and they are still called non-muscle-invasive bladder cancer.
- Invades the muscularis propria. The cancer cells have grown into the bladder wall’s thick muscle layer. This is muscle-invasive bladder cancer, and it is described in our article on invasive urothelial carcinoma.
- Cannot be determined. The pathologist often cannot tell whether invasion is present because the tissue is damaged or poorly oriented. A second TURBT may be done to answer the question.
When papillary urothelial carcinoma invades the lamina propria, the pathologist usually describes how much of this layer is involved, if measurable. The report may give the size or depth of the invasive area in millimeters. It may also say whether the cancer is above or below a thin band of muscle within the lamina propria, called the muscularis mucosae. More extensive invasion is linked to a higher chance that the cancer will grow into the muscle later.
Some papillary urothelial carcinomas grow downward into the lining as smooth, rounded nests, a pattern called inverted growth. This pattern can look like invasion, but on its own it is not counted as invasion. Your report may mention inverted growth to avoid confusion with a more serious finding.
Your report may also mention urothelial carcinoma in situ in the lining near the papillary tumor. Urothelial carcinoma in situ is a flat, high-grade, non-invasive form of the cancer that cannot be seen easily during cystoscopy. When it is found alongside a papillary tumor, the risk of the cancer coming back or growing into the muscle is higher.
Lymphovascular invasion
Lymphovascular invasion means cells from the papillary urothelial carcinoma are seen inside a small blood vessel or a lymphatic channel. Your report may call this “lymphatic and/or vascular invasion,” and it is reported as present, not identified, or cannot be determined. It can only happen once the cancer has invaded below the lining, so it is not seen in non-invasive tumors. When it is present in a pT1 tumor, the risk of the cancer spreading is higher, and your team may discuss more extensive treatment.
Margins
A TURBT removes papillary urothelial carcinoma in many small pieces, so the pathologist cannot tell which edges were cut during surgery. For this reason, pathologists do not report margins on a TURBT specimen. Whether any tumor remains is judged by the urologist during the procedure and by follow-up cystoscopy. If the bladder is later removed in an operation called a cystectomy, the margins are reported as described in our article on the radical cystectomy pathology report.
Biomarker and molecular testing
Biomarker testing for papillary urothelial carcinoma looks for features of the cancer cells that can guide treatment. These tests are not part of most reports for non-invasive tumors. They are usually done only if the cancer becomes advanced, comes back after surgery, or if a clinical trial is being considered. They can be performed on tissue from an earlier TURBT.
FGFR3
FGFR3 is a gene that makes a protein involved in cell growth. Changes in FGFR3 are very common in papillary urothelial carcinoma, especially in low-grade non-invasive tumors. Testing is done with a molecular test such as next-generation sequencing (NGS). The test looks for a mutation or a fusion with another gene.
- Detected. An FGFR3 change was found. If the cancer is advanced, this can make a person eligible for erdafitinib. The FDA granted full approval to erdafitinib in January 2024 for advanced urothelial carcinoma with certain FGFR3 changes, after at least one prior treatment. Clinical trials are also studying drugs targeting FGFR3 for non-invasive tumors.
- Not detected. No FGFR3 change was found. This means FGFR3-targeted drugs are not an option, but other treatments remain available.
HER2
HER2 is a protein on the surface of some cancer cells that helps them grow. In urothelial carcinoma, clinicians test for it by immunohistochemistry, mainly when the cancer is advanced. Results are scored from 0 to 3+.
- 0 or 1+. The cancer cells make little or no HER2.
- 2+. This is an in-between result, and your oncologist can explain what it means in your situation.
- 3+. The cancer cells make a large amount of HER2. In April 2024, the FDA granted accelerated approval to trastuzumab deruxtecan for advanced solid tumors with a HER2 score of 3+, after earlier treatment.
PD-L1
PD-L1 is a protein that some cancer cells use to hide from the immune system. In urothelial carcinoma, it is tested by immunohistochemistry and usually reported as a combined positive score (CPS) or as positive or negative. For most current immunotherapy treatments for urothelial carcinoma, a PD-L1 result is not required. If your report includes a PD-L1 result, your oncologist can explain whether it affects your treatment. Our article on PD-L1 testing in cancer explains how the test works.
Mismatch repair proteins
Mismatch repair proteins fix mistakes that happen when a cell copies its DNA. Testing looks for four proteins called MLH1, PMS2, MSH2, and MSH6. In papillary urothelial carcinoma, it is done most often on tumors from the kidney or ureter, because of their link to Lynch syndrome.
- Intact, retained, or no loss of expression. All four proteins are present. This is the normal result, making Lynch syndrome unlikely.
- Loss of expression. One or more proteins are missing. This result does not confirm Lynch syndrome, but it warrants referral for genetic counseling and a blood test. Advanced tumors with this result may also respond well to immunotherapy.
Our article on mismatch repair across cancer types explains these results in more detail. For more information on tumor testing, visit our Biomarkers and Genetic Testing section.
Pathologic stage (pTNM)
The pathologic stage for papillary urothelial carcinoma of the bladder is assigned using the TNM system from the AJCC Cancer Staging Manual, 8th edition. The tumor stage (pT) describes how deeply the cancer has grown. The nodal stage (pN) describes spread to lymph nodes and is assigned only when lymph nodes are removed. Spread to distant organs (M) is usually determined by imaging rather than by the pathology report.
Tumor stage (pT)
- pTa. The tumor is non-invasive papillary carcinoma. This is the stage of most papillary urothelial carcinomas.
- pTis. The report shows flat urothelial carcinoma in situ. If it is found alongside a papillary tumor, your report may list both.
- pT1. The tumor has grown into the lamina propria but not into the muscle layer.
- pT2. The tumor has grown into the muscularis propria.
- pT3. The tumor has grown through the muscle into the fat around the bladder.
- pT4. The tumor has grown into a nearby organ, such as the prostate, uterus, or vagina, or into the wall of the pelvis or abdomen.
A TURBT can show whether the cancer has reached the muscle, but it cannot show stages pT3 or pT4. Those stages are assigned only after the bladder is removed.
Nodal stage (pN)
Lymph nodes are not removed during a TURBT, so most reports for papillary urothelial carcinoma do not include a nodal stage. If lymph nodes are removed during a cystectomy, the nodal stage is assigned as follows:
- pN0. No cancer was found in the examined lymph nodes.
- pN1. Cancer was found in a single pelvic lymph node.
- pN2. Cancer was found in more than one lymph node in the pelvis.
- pN3. Cancer was found in lymph nodes along the common iliac arteries, which are higher in the pelvis.
Papillary urothelial carcinomas that start in the kidney or ureter are staged with slightly different definitions, because the wall of these organs is thinner than the wall of the bladder.
What is the prognosis?
The prognosis for papillary urothelial carcinoma depends mostly on the grade and on whether the cancer has invaded the bladder wall. For most people with a non-invasive tumor, the outlook is very good. However, these tumors often come back in the bladder, which is why regular follow-up is needed.
- Non-invasive tumors. About 98 in 100 people with non-invasive bladder cancer are alive five years after diagnosis, and about 2 in 100 are not. About half of all bladder cancers are found at this stage.
- Low-grade tumors. New tumors often appear in the bladder after treatment, but they are usually low-grade and non-invasive again. Only a small number ever grow into the muscle.
- High-grade tumors. These are more likely to recur and grow into the muscle, even when they start as non-invasive tumors—close follow-up and treatment with medicine placed in the bladder lower this risk.
- Tumors that have invaded the bladder wall but not spread. About 73 in 100 people are alive five years after diagnosis, and about 27 in 100 are not. This group includes tumors that have reached the muscle, which have a less favorable outlook than pT1 tumors.
These numbers are averages for large groups of people and don’t predict what will happen to you. Features in your report that are linked to a higher chance of the cancer coming back or growing deeper include:
- High grade. Tumor cells that look very different from normal urothelial cells.
- Invasion of the lamina propria. A pT1 tumor, especially when the invasion is extensive.
- Carcinoma in situ. Flat cancer in the lining near the papillary tumor.
- Lymphovascular invasion. Cancer cells inside small vessels, which can carry them to other parts of the body.
- Several or large tumors. More than one tumor, or a tumor larger than 3 cm, as described by your urologist.
- A tumor that has come back. Especially a high-grade tumor that comes back despite treatment.
What happens after the diagnosis?
After a diagnosis of papillary urothelial carcinoma, your care team uses the grade, depth of invasion, and other findings in your report to plan treatment. Your urologist combines these findings with the number and size of the tumors. Together they place the cancer in a low-, intermediate-, or high-risk group, which guides treatment and the follow-up schedule.
- Low-grade non-invasive tumors. The TURBT itself often removes the cancer completely. A single dose of chemotherapy medicine may be placed in the bladder soon after the TURBT to lower the chance of new tumors. In June 2025, the FDA approved a form of mitomycin placed in the bladder for some people whose low-grade tumors keep coming back. It can be used instead of repeat surgery.
- High-grade non-invasive tumors and pT1 tumors. A second TURBT is often done to make sure no tumor remains and that muscle has been sampled. Doctors then usually place medicine in the bladder through a catheter, most often BCG, a weakened bacterium that stimulates the immune system. In May 2026, the FDA approved durvalumab with BCG for some people with high-risk tumors who have not had BCG before.
- Tumors that come back after BCG. If a high-grade tumor returns despite BCG, removing the bladder is often discussed. Several newer medicines are FDA-approved for some people in this situation, mainly when carcinoma in situ is also present.
- Muscle-invasive tumors. These are treated as invasive urothelial carcinoma, usually with chemotherapy and surgery or radiation.
Drug approval and access differ by country, and your care team can explain what applies where you live. Follow-up for papillary urothelial carcinoma includes regular cystoscopy, often with urine tests and imaging. Checks are more frequent in the first few years and for high-grade tumors.
Questions to ask your doctor
- Is my papillary urothelial carcinoma low grade or high grade?
- If my tumor has both grades, what percentage is high grade?
- Is the tumor non-invasive, or has it grown into the lamina propria?
- If there is invasion, how extensive is it?
- Was muscle included in my TURBT sample, and do I need a second TURBT?
- Was carcinoma in situ found in the lining near the tumor?
- Was lymphovascular invasion found?
- What is the stage of my cancer?
- Is my cancer low risk, intermediate risk, or high risk?
- Will I receive medicine placed in my bladder, such as chemotherapy or BCG?
- Should my kidneys and ureters be checked for other tumors?
- How often will I need cystoscopy, and for how long?
- Would biomarker testing, such as FGFR3, be useful for me now or in the future?