Scrotal tuberculosis

Scrotal tuberculosis is a rare manifestation of extrapulmonary tuberculosis. It includes tuberculous orchitis and epididymitis.

Epidemiology

It is rare, and representing only represents about 3% of the cases of genitourinary tuberculosis ².

Clinical presentation

It presents as a painless or slightly painful scrotal mass and so it is harddifficult to differentiate this entity from usualtypical epididymo-orchitis or other conditions such as tumours or infarctionsinfarction ¹. 

Pathology

Infection usually affects the epididymis first and then can affect the testis if not treated. It is believed to occur due to a retrograde extension from the prostate and seminal vesicles as well as hematogeneoushaematogenous spread ¹.

Radiographic features

Ultrasound

Scrotal tuberculous typically begins in the tail of epididymis as it is most vascular and also the ductus (vas) deferens as it is affected by urinary reflux.

Tuberculous epididymitis: appears as a diffuse heterogeneous predominantly hypoechoic enlarged epididymis or an intrinsic focal nodular hypoechoic lesion. It usually shows increased colour Doppler flow differentiates this condition, differentiating it from infarction. Bilateral involvement is common rather than, unlike other non-tuberculous infectioninfections.

TuberculosisTuberculous orchitis: usually preceded or associated with epididymitis. Different sonographic patterns have been described ¹:

• diffusely enlarged heterogeneously hypoechoic testis
• diffusely enlarged homogeneously hypoechoic testis
• nodular enlarged heterogeneously hypoechoic testis
• multiple small hypoechoic nodules in thean enlarged testis (miliary type) 

Other associated findings:

• thickened scrotal skin
• scrotal sinus tract
• scrotal hydrocele
• scrotal abscesses
• intrascrotal extratesticular calcification: at epididymis and tunica vaginalis 
• evidence of tuberculosis infection elsewhere

Treatment and prognosis

Antituberculous chemotherapy is the mainstay of treatment. Orchidectomy is rarely required for diagnosis or treatment. It may result in infertility ³.

Differential diagnosis

• bacterial epididymo-orchitis
• sarcoidosis
• lymphoma
• primary testicular tumours
• testicular metastasis
• testicular haematoma 
• testicular infarction

Practical points

• a heterogeneous, enlarged epididymis is more commonly seen with tuberculous rather than nontuberculous involvement thatnon-tuberculous epididymitis (which usually appears homogeneous)
• bilateralitybilateral involvement is more common with tuberculous etiologyepididymo-orchitis
• failure of antibiotic therapy offor epididymo-orchitis should raise the concern ofsuspicion for a tuberculous etiologyaetiology
• the presence of pulmonary or extrapulmonary tuberculosis infection elsewhere often makes scrotal manifestations more likely to be tuberculous
• associated features which are unusual associations ofin non-tuberculous epididymo-orchitis (such as intrascrotal extratesticular scrotal calcifications, scrotal abscess, and sinus tracttracts) are helpful clues