Emphysematous epididymo-orchitis

Introduction:

Emphysematous epididymo-orchitis is a rarely reported entity with only a handful of case reports which still lacks a strong evidence for the existence of the disease. It is reported as a rare cause of acute scrotum encountered in poorly controlled diabetics. The most common symptoms are pain, swelling, reddening and local rise in temperature and thus clinically in differentiable from other causesPathology of acute scrotumthis condition is unknown with few possible hypotheses postulated. Diagnosis is usually made by ultrasonography with computed tomography done to confirm the diagnosis, evaluate the extent of emphysematous spread of infection and to rule out coexistent retroperitoneal source. Pathology of this rare condition is unknown with few possible hypotheses postulated. It has a high mortality and requires emergent orchidectomy.

Epidemiology:

Emphysematous epididymo-orchitis is a rarely reported pathology with only five cases reported in English literature. Typically a poorly controlled elderly diabetic patient presents with acute scrotum with other epidemiological factors unknown.

Clinical presentation:

It is an acquired condition withAll case reports published had spontaneous presentation. Onset of sudden onset testicular pain is sudden which does not relieve with scrotal elevation. It is associated with local inflammation i.e. swelling, reddening and local rise in temperature. There may be associated fever, leucocytosis, pyuria and bacteriuria. 

Pathology:

Pathology of this entity is unknown with Diabetes being a predisposing factor as with other emphysematous infections. Following hypotheses are postulated:

• Coexistent retroperitoneal emphysematous infection adjacent to origin of testicular artery with involvement of ipsilateral testis.
• Rupture of sigmoid diverticula into the seminal vesicle as a source of air within the testis.

Radiographic features:

Ultrasonography

Hyperechoic foci within the testicular parenchyma showing posterior dirty shadowing and reverberation artefacts or a curved hyperechoic line conforming to the globular shape of testis is seen on high resolution ultrasound of scrotum suggest the diagnosis. This hyperechogenicity needs to be differentiated from testicular microliths, sutures and foreign body. Presence of posterior dirty shadowing, reverberation artefacts and clinical profile help differentiate these entities.  There may be associated reactive hydrocele, funiculitis and scrotal wall thickening with increased vascularity.

CT

CT is the modality of choice to demonstrate intratesticular air. Hypodense foci / patchy areas (Hounsfield unit = -1000) noted within the testicular parenchyma confirm the diagnosis. CT also helps in determining the extent of spread of infection. Also abdominal sections may point toward other associated conditions like sigmoid diverticulae and retroperitoneal emphysematous infections.

MRI

Can confirm the presence of air within the testis but is time consuming and does not add any further to the diagnosis. Thus MRI in these cases is not recommended as delays the emergent orchidectomy.

Treatment and prognosis:

Time is the key to successful management. Emergent orchidectomy is the treatment of choice with secondary management of predisposing condition like retroperitoneal infection / sigmoid diverticulae. Strict control of diabetes may help prevent this condition. Prognosis is usually worse.

Differential diagnosis:

Differentials of clinical acute scrotum:

• Epididymo-orchitis
• Testicular torsion
• Fournier’s gangrene
• Torsion of testicular appendage
• Testicular trauma

Imaging differential:

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• Fournier’s gangrene with testicular involvement: Differentiation between emphysematous epididymo-orchitis and Fournier’s gangrene with testicular involvement is a challenge even radiologically. Presence of air within the subcutaneous plane with necrotizing fasciitis of perineal, genital and perianal regions point towards this entity. This is rarely reported with such cases having retroperitoneal source of infection highlighting the difference in arterial supply of testis (testicular artery from aorta) and scrotal wall (branches from internal iliac artery).