GENITOURINARY TUBERCULOSIS
Category: Urology
Abstract : Tuberculosis (TB) of the genitourinary (GU) tract is caused by Mycobacterium
tuberculosis. TB predominantly affects Asian populations, with a higher
incidence in males than females. Pathogenesis Primary TB The primary
granulomatous lesion forms in the mid to upper zone of the lung. It consists of
a central area of caseation surrounded by epitheloid and Langhans giant
cells
Tuberculosis (TB) of the genitourinary (GU) tract is caused by Mycobacterium
tuberculosis. TB predominantly affects Asian populations, with a higher
incidence in males than females.
Pathogenesis
Primary TB
The primary
granulomatous lesion forms in the mid to upper zone of the lung.
It consists of
a central area of caseation surrounded by epitheloid and Langhans giant
cells, accompanied by caseous lesions in the regional lymph nodes. There is
early spread of bacilli via the bloodstream to the GU tract; however, immunity
rapidly develops, and the infection remains quiescent. Acute diffuse systemic
dissemination of tubercle bacilli can result in symptomatic miliary
TB.
Post primary TB
Reactivation of infection is triggered by immune
compromise (including HIV). It is at this point that patients develop clinical
manifestations.
Kidney
Haematogenous spread causes granuloma formation
in the renal cortex, associated with caseous necrosis of the renal papillae and
deformity of the calyces, leading to release of bacilli into the urine. This is
followed by healing fibrosis and calcification, which causes destruction of
renal architecture and autonephrectomy.
Ureters
Spread is directly
from the kidney, and can result in stricture formation (vesicoureteric junction,
pelvi-ureteric junction, and mid-ureteric) and ureteritis
cystica.
Bladder
Usually secondary to renal infection, although
iatrogenic TB can be caused by intravesical BCG treatment for carcinoma in situ.
The bladder wall becomes oedematous, red, and inflamed, with ulceration and
tubercles (yellow lesions with a red halo). Disease progression causes fibrosis
and contraction (resulting in a small capacity thimble bladder),
obstruction, and calcification.
Prostate and seminal
vesicles
Haematogenous spread causes cavitation and calcification, with
palpable, hard-feeling structures. Fistulae may form to the rectum or
perineum.
Epididymis
Haematogenous spread results in a
beaded cord. Infection may spread to the
testis.
Presentation
Early symptoms include fever, lethargy, weight
loss, night sweats, and UTI not responding to treatment. Later manifestations
include LUTS, haematuria, and flank pain.
Investigations
- Urine: at
least 3 early morning urines (EMUs) are required, but often many more EMU
specimens will be needed before a positive culture for TB is obtained. A typical
finding is sterile pyuria (leucocytes, but no growth). Ziehl - Neelsen staining
will identify these acid- and alcohol-fast bacilli (cultured on Lowenstein -
Jensen medium).
- CXR and sputum.
- Tuberculin skin test.
- IVU:
findings include renal calcification, irregular calyces, infundibular stenosis,
cavitation, pelviureteric and vesicoureteric obstruction, and a contracted,
calcified bladder.
- Cystoscopy and biopsy.
Treatment
6 months of
isoniazid, rifampicin, and pyrizinamide (see BNF). Regular follow-up imaging
with IVU is recommended to monitor for ureteric strictures, which may need
stenting, nephrostomies, or ureteric reimplantation. Severe bladder disease may
require surgical augmentation, reconstruction, or urinary diversion.
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