PRESENTATION AND DIAGNOSIS

The symptoms of genitourinary tuberculosis can be very nonspecific. Patients often complain of urinary frequency and may, in some cases, experience gross hematuria or flank pain. Some patients may also have constitutional symptoms, including fever and weight loss.

About 90% of patients will have abnormal urinalysis, which may reveal positive leukocyte esterase, hematuria, proteinuria, and low urine pH. About 1 in 10 patients will have only frank hematuria, whereas up to half have microscopic hematuria. As Mycobacterium tuberculosis does not convert urinary nitrates, dipstick is often negative for nitrites.

The classic urinary finding—found in up to one quarter of patients—is sterile pyuria, where urine contains numerous white blood cells but no bacterial growth is seen on standard cultures. Of note, bacterial growth does not necessarily rule out renal tuberculosis, since secondary bacterial infection is common.

If sterile pyuria is seen, the differential diagnosis also includes chlamydial urethritis, pelvic inflammatory disease, nephrolithiasis, or renal papillary necrosis. If constitutional symptoms and hematuria are present, a malignancy of the urinary or genital system should also be suspected.

A physician may suspect urogenital tuberculosis if the patient has risk factors for tuberculosis exposure, a history of a positive purified protein derivative (PPD) test, a history of immunocompromise, and constitutional symptoms. It is not uncommon, however, for physicians to prescribe antibacterial treatment at first presentation. A lack of positive urine cultures, no response to antimicrobials, or recurrent episodes of cystitis in the setting of suggestive risk factors should raise a suspicion of mycobacterial infection and prompt further evaluation.

A radiograph may reveal areas of focal calcification in the kidneys and the lower genitourinary tract. Ultrasonography may reveal calcification, hypoechoic renal abscesses, and shrunken kidneys. CT may demonstrate calcifications, renal scarring and cavitation, papillary necrosis, strictures of the collecting system, and diminution of renal function. Imaging of the thorax should also be performed to rule out concomitant pulmonary or spinal infection. Many patients will have evidence of prior pulmonary infection, and up to 30% to 40% will be found to have active pulmonary disease.