If you’ve noticed blood in your urine (hematuria), have urinary irritation that doesn’t improve, or have a history of urothelial cancer, your doctor may order several tests to understand what’s going on. In most cases, the workup includes a combination of clinical evaluation, imaging studies, cystoscopy, and laboratory testing.
As part of that process, urine cytology can be helpful. But sometimes the report doesn’t provide a clear answer and may come back as “atypical” or “inconclusive.” When that happens, a molecular test such as UroVysion FISH can provide additional information to help guide the next step—always interpreted alongside the rest of the findings.
1) Why cytology may be inconclusive
Cytology examines cells in the urine under a microscope. It’s a valuable test, but it doesn’t detect everything.
It may be less helpful when:
- the lesion is small or low-grade
- there is inflammation or a recent infection
- there have been urinary procedures or instrumentation (for example, a catheter)
- reactive cellular changes make the cells harder to interpret
That’s why an “atypical” result doesn’t automatically mean something serious—it means more information is needed.
2) What UroVysion FISH is
UroVysion FISH is an advanced urine test that analyzes the genetic material (DNA) of cells.
Instead of looking only at the shape of cells, it looks for internal changes that, in some cases, can be associated with urothelial cancer (cancer that affects the inner lining of the bladder and parts of the urinary tract).
The most important thing to know:
UroVysion FISH does not diagnose cancer on its own and does not replace cystoscopy.
It is used as supportive information to help the doctor decide the next step.
3) When UroVysion FISH is used
Your doctor may consider it when more clarity is needed, for example in:
- Hematuria evaluation as part of a more complete workup
- Follow-up (surveillance) in patients with a history of urothelial cancer, to detect changes early
- Atypical or equivocal cytology, when additional evidence is needed to decide whether to repeat testing or proceed with other procedures
4) What a “positive” or “negative” result means
It’s normal to feel worried when you see test results. Here is a general guide (always review with your doctor):
- Positive result:
Suggests that changes were detected in the sample that are compatible with alterations associated with urothelial carcinoma.
It is not a final diagnosis on its own, but it can increase suspicion and support closer follow-up. - Negative result:
No such changes were detected in the analyzed sample.
Even so, it does not rule out the condition 100%, because sometimes the sample may not contain enough abnormal cells at that moment.
In some cases, an “anticipatory positive” can occur: the result suggests changes before other methods clearly identify a lesion. That’s why clinical context is essential.
5) How the sample is collected (what you should know)
Depending on the case, the urologist may request:
- Voided urine (a spontaneous urine sample)
- Catheterized sample
- Bladder washing/irrigation (barbotage) (as indicated)
What to do next (recommended steps)
If urine cytology or UroVysion FISH was ordered, these three steps can help:
- Ask your doctor: “What does this result mean in my specific case?”
- Confirm what type of sample you need and how to prepare
- Ask whether the next step will be repeat cytology, cystoscopy, imaging, or other follow-up
Frequently Asked Questions (FAQ)
Does UroVysion FISH detect bladder cancer with certainty?
Not by itself. It provides molecular evidence and is interpreted along with medical evaluation (including cystoscopy/biopsy when indicated).
If my cytology was “atypical,” does that mean I have cancer?
Not necessarily. “Atypical” indicates cellular changes that require correlation and, sometimes, additional testing to clarify the findings.
Is it used more for detection or follow-up?
It is used for both, and it is commonly used for recurrence surveillance and hematuria evaluation based on medical judgment.
If your doctor or urologist ordered an evaluation that includes urine cytology or UroVysion FISH, you can contact HRP Labs for guidance on the process and sample collection: 787-765-7320 or servicioalcliente2@hrplabs.com.