A 50-year-old man presented with left testicular pain, a history of acute epididymitis and abscess formation. He underwent orchidectomy and histology revealed granulomatous epididymo-orchitis (Fig. 1a).
A 56-year-old woman was investigated for macroscopic haematuria secondary to a urinary infection; no organism was cultured. A staghorn calculus was diagnosed. She had persistent sterile pyuria and irritative symptoms. Cystoscopy revealed an inflamed bladder and biopsies revealed granulomatous cystitis (Fig. 1b).
A 53-year-old man was investigated for penile cellulitis and obstructive urinary symptoms. The palpable urethral thickening was biopsied at urethroscopy; histology revealed granulomata (Fig. 1c).
Ziehl-Neelsen (ZN) staining of tissue samples was negative in all three patients. In patient nos 1 and 2, three early morning urine (EMU) samples cultured on Lowenstein-Jensen slopes revealed Mycobacterium tuberculosis, but in no. 3 it was the sixth EMU that eventually revealed the diagnosis.
The prevalence of tuberculosis may be as high as 400 in 100 000 in some developing countries, as opposed to 5–12 in 100 000 in the UK ; only 20% of these cases occur in the white population. Genitourinary tuberculosis accounts for 14% of non-pulmonary manifestations  and therefore 1–1.5 cases per year present to a urologist serving a population of 500 000. Atypical acute or chronic urological disease should warrant the active exclusion of tuberculosis. The use of ZN stains on histological sections of genitourinary tissue aid in confirming the diagnosis when positive, but they are usually negative . Negative results should never exclude the diagnosis. Microscopy of EMUs with ZN staining is unrewarding because there is much debris in the urine sample. The urine must be cultured on Lowenstein-Jensen slopes for up to 9 weeks. At least six EMUs should be requested, and more if tuberculosis is clinically or histologically suspected.
D. Cahill, Bsc, FRCS, Specialist Registrar in Urology.