The most ominous sign or symptom of urinary system disease is:

E. Hematuria.

DISCUSSION: While urinary frequency (voiding more than three to five times daily) or dysuria (painful voiding) may be a sign of malignant disease, they are more commonly associated with nonmalignant inflammatory disease, neurologic disease, or calculous disease of the urinary tract. Pyuria (pus in the urine) is most commonly associated with infection and not malignancy. Pneumaturia (air or gas in the urine) indicates a fistula between bowel and the urinary tract or infection by fermination in diabetic urine. Hematuria (blood in the urine) is most worrisome. While this may be produced by infection or by calculous disease, it is most commonly associated with malignant disease in the absence of associated signs or symptoms such as pyuria, frequency, and dysuria. Thus, of the ones mentioned, hematuria is the most ominous single sign or symptom.