I have enlarged prostate and from what I understand this can occasional cause blood in urine.i had cyscopsy 5 months ago and no cancer in bladder.recently they found a little microscopic blood in my urine.since the cyscopy was normal 5 months ago cant they just do urine cytology insteas of repeating the tests

Frank, let me start out by attaching the following "macro" I have written on blood in the urine.  After that, I will refer specifically to your case.

Although red discoloration of the urine is usually due to blood, it may also occur from the excretion of some pigments in the foods we eat.  The most common are from beets, rhubarb, & blackberries.  Certain medications & chronic toxicity from lead or mercury may produce red urine as well.

There are many possible causes for blood in the urine (hematuria).  The origin of the bleeding can come from the upper (kidneys or ureters) or lower (bladder, prostate, urethra) urinary tract.  Blood seen only under the microscope (microscopic hematuria) is usually of a benign nature whereas gross hematuria is potentially more serious. With gross hematuria, it is important to note the relationship of the bleeding to the urinary stream.  If at the beginning of urination (initial hematuria), the source of the blood is almost always in the urinary canal (urethra).  If at the end of urination (terminal hematuria), the source is usually the prostate gland in men or the bladder neck in men and women.  Bleeding throughout the entire stream (total hematuria) is due to bleeding that is initiated in the urinary bladder or upper urinary tract (kidneys and/or ureters).  

Some of the common causes of hematuria include infection, tumors, stones, and trauma (injury).  In order to look for the cause, it is necessary to consult a urologist.  A history, physical examination, urine cytology, and other laboratory tests are done.  In recent years, the FISH assay of the urine has been used in lieu of or in place of the urinary cytology.  This test has proven to be much more sensitive and specific in detecting bladder cancer in voided urine specimens or bladder washings. Visualization of the kidneys by imaging studies (ie IVP, ultrasound, CT or MRI) and examination of the lower urinary tract with a cystoscope are usually required.  

In 80% of patients with microscopic hematuria a cause is found and 2-3% of these are  found to have a urologic cancer.  Microscopic hematuria can also be due to inflammatory disorders of the kidney, so called nephritis, of which there are many types. Even with studies, often no specific cause is found (in about 20%) for microscopic hematuria and this is termed “essential hematuria”.  The American Urologic Association has recently revised their guidelines for the evaluation of  microscopic hematuria.  This is defined as 3 RBC or greater per high power field in at least 2 of 3 properly collected specimens.  If no cause is found for the hematuria on initial evaluation, the patient is periodically re-evaluated & followed for 3 years.  If the patient remains stable for 3 years, routine followup is no longer recommended.   The exceptions would be those persons with increased risk factors for cancer such as smoking, history of gross hematuria, irritative voiding symptoms, exposure to chemicals or dyes (benzenes or aromatic amines), urinary tract infections, history of pelvic irradiation, analgesic abuse, and age greater than 40. 

You did not mention why you had the initial evaluation done.  I assume it was because of an enlarged prostate gland as opposed to microscopic hematuria.  For practical purposes, it really does not matter.  As prostates enlarge, they often develop friable veins on their surface.  These are predisposed to bleeding which can be either gross or microscopic.  However, because there are so many other causes for hematuria, I would recommend that you at least have an imaging study of the upper urinary tract as mentioned above.  In addition, a FISH assay or cytology of the urine should be done to look for malignant cells.  There is no need for a repeat cystoscopy at this time.   If no cause is found for the hematuria, I recommend a yearly urinalysis for the next 3 years.  If RBCs are found, I generally do one of these 3 initial tests annually on a rotating basis.  If no cause is found, you can discontinue screening unless you have one of the risk factors mentioned above or grosses hematuria occurs.  Good luck.  


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Arthur Goldstein, M.D.


Problems or questions related to the field of urology; ie urinary stone disease, urinary cancers (kidney, bladder, prostate, testis, etc.), urinary infections, etc. I no longer answer questions related to erection problems or male sexual dysfunction.


I am retired from the active practice of urology. My 34 years was totally in the clinical field and involved the entire gamut of genitourinary problems, with special interest in endourology.

American Medical Association, American Urological Association, American College of Surgeons

College degree - BS Medical degree - MD Master of Science - MS

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