Negative or Atypical Urine Cytology: How Should Results Be Interpreted?

Quick answer

Urine cytology examines cells in urine under a microscope. A negative result alone does not reliably rule out a bladder tumour. An atypical result is not, by itself, a cancer diagnosis. The report is interpreted alongside symptoms, previous tumour history and findings such as cystoscopy.

Are cytology, urinalysis and culture the same test?

• Urinalysis provides information about blood, protein and other urine features.
• Culture looks for microorganisms that can cause infection.
• Cytology assesses the appearance of cells.

A normal result in one test does not automatically answer the question addressed by another. Knowing why each test was requested helps avoid misinterpreting a single negative result.

References for this section: American Cancer Society. Tests for bladder cancer.

Does negative cytology mean there is no cancer?

No. Cytology is more helpful in assessing high-grade disease and more limited in detecting low-grade tumours. An insufficient number of cells can also affect interpretation. Negative for high-grade urothelial carcinoma should not be read as an all-clear for every tumour type.

Do atypical and suspicious mean different things?

Atypical means that some cells look unusual; it does not establish cancer by itself. A suspicious result is a different category and may require further assessment. An inadequate sample is another separate finding. These terms should not be used interchangeably without reading the full diagnostic line.

How does the Paris System standardise cytology reporting?

The Paris System focuses particularly on detecting high-grade urothelial carcinoma in urinary cytology. The framework paper by Barkan and colleagues explains the purpose of this shared reporting language. When comparing laboratories, check the full diagnostic category and reporting system rather than relying only on an abbreviation.

This table summarises common categories; it does not cover every diagnosis or classification detail. In particular, “atypical” and “suspicious” should not be treated as interchangeable everyday words.

References for this section: Barkan GA, Wojcik EM, Nayar R, et al. The Paris System for Reporting Urinary Cytology: The Quest to Develop a Standardized Terminology. Acta Cytol. 2016;60(3):185-97.

Why does a negative result mean different things in different patients?

Pre-test suspicion and previous pathology affect interpretation. Yamasaki and colleagues compared cytology with TURBT tissue before and after adopting the Paris System. Standardisation was helpful, but a negative result did not exclude every high-grade case. A study’s negative predictive value cannot be transferred directly to a population with different characteristics.

For someone with previous high-grade tumour or CIS, a new negative cytology does not automatically replace planned cystoscopy. In someone without a prior tumour diagnosis, cytology alone should not be treated as a general-population screening test. The question being investigated matters as much as the result.

References for this section: Yamasaki M, Taoka R, Katakura K, et al. The Paris System for reporting urinary cytology improves the negative predictive value of high-grade urothelial carcinoma. BMC Urol. 2022;22(1):51. American Cancer Society. Can bladder cancer be found early?

Can BCG or infection affect the result?

Infection, stones and intravesical treatments can make cell assessment more difficult. Tell the team about recent cystoscopy, TURBT or BCG when providing the sample. Nevertheless, do not dismiss an abnormal result as merely due to treatment; discuss whether another sample is needed.

References for this section: EAU. Non-muscle-invasive Bladder Cancer: Diagnosis — TURBT, second resection and pathology report.

Does a positive result show exactly where the tumour is?

Cells in cytology can come from different parts of the urinary tract. The result therefore does not locate a tumour by itself. If suspicion of high-grade disease remains despite no obvious bladder lesion, further assessment of the bladder and other appropriate sites may be planned. The investigations depend on previous findings.

How is the next step chosen after an atypical result?

First review sample adequacy, symptoms, infection or recent procedures and previous cancer history together. The clinician may recommend a repeat sample at an appropriate time, cystoscopy, imaging or biopsy of a suspicious area. Not every atypical result means immediate surgery, but attributing every atypical result to infection is also inappropriate.

BCG can cause treatment-related cellular changes. Moulavasilis and colleagues related cytology categories after BCG to subsequent tissue findings. Their study supports interpreting post-treatment reports in context. Its figures describe a selected research group; they cannot independently establish your personal probability of cancer.

References for this section: Moulavasilis N, Stravodimos K, Meletis E, et al. The Paris system classification for urinary cytology in patients under bacillus Calmette-Guerin treatment. Diagn Cytopathol. 2022;50(6):289-294.

Which information should accompany the sample?

Specify whether the specimen is voided urine, a catheter sample or bladder-wash fluid. Recent TURBT, cystoscopy or BCG and a known tumour history matter for interpretation. Follow the laboratory’s instructions for containers, collection and delivery; do not assume different specimen types are interchangeable.

A negative culture and negative cytology are different findings: one concerns microbial growth, the other cell appearance. Negative cytology does not remove the need to assess a suspicious cystoscopic area. When tests seem inconsistent, discuss the discrepancy instead of selecting only the reassuring result.

References for this section: EAU. Non-muscle-invasive Bladder Cancer: Diagnosis — TURBT, second resection and pathology report. National Cancer Institute. Bladder Cancer Diagnosis.

Do newer urine tests completely replace cystoscopy?

Urine biomarkers are not the same as cytology. Some may help in particular diagnostic or follow-up settings, but that does not mean one test can replace every investigation for every patient. Discuss the population in which a test was evaluated, false-negative and false-positive results, and whether the result would change treatment. A product's sensitivity percentage alone should not determine an individual's surveillance.

References for this section: American Cancer Society. Can bladder cancer be found early?

Preparing for the results appointment

Bring the full report, sample date and dates of recent procedures or treatment. Ask: Does this fit my previous findings? Do I need another sample or a biopsy? Will my planned cystoscopy change? Do not postpone follow-up based only on an online explanation of a term.

Which questions should I ask about biomarker tests?

Cytology examines cells microscopically; molecular biomarkers measure different features. Trials such as DaBlaCa-15 tested a specific assay alongside, or alternating with, cystoscopy at defined intervals. Simply knowing that a urine test was used is insufficient: its name, purpose and the follow-up step it changes are important.

Ask which risk group the assay was studied in, what happens after a positive or negative result and how much is known about long-term safety. The availability of a new test does not mean everyone needs additional testing. A result that cannot alter a clinical decision may add information without changing care.

References for this section: Dreyer T, Brandt S, Fabrin K, et al. Use of the Xpert Bladder Cancer Monitor Urinary Biomarker Test for Guiding Cystoscopy in High-grade Non-muscle-invasive Bladder Cancer: Results from the Randomized Controlled DaBlaCa-15 Trial. Eur Urol. 2025;88(1):23-30.

Frequently asked questions

Do atypical cells definitely mean cancer?

No. An atypical result is interpreted alongside clinical information and other investigations. It should neither be treated as a definite cancer diagnosis nor dismissed as unimportant.

Does a negative culture mean cytology is normal too?

No. Culture examines microorganisms and cytology examines cell features. They answer different questions.

Does positive cytology mean the bladder will be removed?

That result alone cannot determine such an operation. The disease site, pathology, stage and other findings must be established before options are assessed.

Sources

1. European Association of Urology. EAU. Non-muscle-invasive Bladder Cancer: Diagnosis — TURBT, second resection and pathology report [Internet]. Available from: https://uroweb.org/guidelines/non-muscle-invasive-bladder-cancer/chapter/diagnosis
2. American Cancer Society. Tests for bladder cancer [Internet]. Available from: https://www.cancer.org/cancer/types/bladder-cancer/detection-diagnosis-staging/how-diagnosed.html
3. American Cancer Society. Can bladder cancer be found early? [Internet]. Available from: https://www.cancer.org/cancer/types/bladder-cancer/detection-diagnosis-staging/detection.html
4. National Cancer Institute. Bladder Cancer Diagnosis [Internet]. Available from: https://www.cancer.gov/types/bladder/diagnosis
5. Barkan GA, Wojcik EM, Nayar R, Savic-Prince S, Quek ML, Kurtycz DF, et al. The Paris System for Reporting Urinary Cytology: The Quest to Develop a Standardized Terminology. Acta Cytol. 2016;60(3):185-97. doi:10.1159/000446270 · PubMed
6. Yamasaki M, Taoka R, Katakura K, Matsunaga T, Kani N, Honda T, et al. The Paris System for reporting urinary cytology improves the negative predictive value of high-grade urothelial carcinoma. BMC Urol. 2022;22(1):51. doi:10.1186/s12894-022-01005-8 · PubMed
7. Moulavasilis N, Stravodimos K, Meletis E, Levis P, Leftheriotis V, Lazaris A, et al. The Paris system classification for urinary cytology in patients under bacillus Calmette-Guerin treatment. Diagn Cytopathol. 2022;50(6):289-294. doi:10.1002/dc.24952 · PubMed
8. Dreyer T, Brandt S, Fabrin K, Azawi N, Vásquez JL, Ernst A, et al. Use of the Xpert Bladder Cancer Monitor Urinary Biomarker Test for Guiding Cystoscopy in High-grade Non-muscle-invasive Bladder Cancer: Results from the Randomized Controlled DaBlaCa-15 Trial. Eur Urol. 2025;88(1):23-30. doi:10.1016/j.eururo.2025.03.018 · PubMed