CASE 13077 Published on 13.10.2015

The “fountain sign” in a case of idiopathic scrotal oedema, combined with cryptorchidism

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Vasileios Rafailidis1, Athanasia Mimila2, Christina Urumowa2, Dimitrios Rafailidis2

1. Radiology Department of AHEPA University Hospital, Thessaloniki, Greece
2. Radiology Department of Gennimatas General Hospital of Thessaloniki, Greece
Email:billraf@hotmail.com
Patient

9 years, male

Categories
Area of Interest Genital / Reproductive system male, Genital / Reproductive system female ; Imaging Technique Ultrasound, Ultrasound-Power Doppler, Ultrasound-Colour Doppler, Image manipulation / Reconstruction
Clinical History
The boy presented with scrotal swelling and erythema of acute onset, more prominent on the right hemiscrotum. The scrotum was mildly painful. The symptoms had started 6 hours before. The scrotum was easily compressible and there was no history of trauma.
Imaging Findings
A scrotal ultrasound using a high frequency linear array transducer was requested to exclude testicular torsion. Gray-scale ultrasound revealed prominent oedema of the scrotal wall, which appeared thickened. (Fig. 1) There was also bilateral thickening of the tunica but no evidence of abscess formation or any gas bubbles within the scrotum. The scrotal layers appeared hyperechogenic bilaterally and measured 9 mm in thickness in the area between the two testes. There were no enlarged inguinal lymph nodes. This examination also identified a sliding right testis and cryptorchidism on the left side. (Fig. 2, 3) The testes were normal in size and echogenicity, without any focal lesions. Colour Doppler technique demonstrated increased blood flow signals confined within the scrotal wall. The signals pattern created the “fountain sign”. (Fig. 4, 5) These findings suggested the diagnosis of acute idiopathic scrotal oedema and the boy recovered fully after a few days of conservative treatment and activity restriction.
Discussion
The term “Acute idiopathic scrotal oedema” (AISE) refers to a rare, benign and self-limiting disease of the scrotal wall, which presents with scrotal oedema, erythema and pain. It affects boys more frequently than adult patients. [1, 2] AISE was firstly described by Qvist et al in 1959, having an incidence of 20%. [3] Different authors report an incidence of more than 60% when it comes to patients younger than 10 years. [1] The exact cause of this disease is not known yet, but it is considered to represent a form of allergic reaction or infection. [1, 4] The possibility of an allergic aetiology can be supported by the eosinophilia found by some authors in patients with AISE. [5] It can be either unilateral or bilateral and in some cases it extends to the perineum or inguinal region in almost half of patients. [2]
Ultrasound represents the primary imaging modality used to evaluate young boys with acute scrotum. Gray scale sonography usually reveals a hypoechoic and thickened scrotal wall in both sides due to oedema. The oedema affects primarily the skin and dartos fascia while the deeper layers of the scrotal wall are normal. Sometimes, a heterogeneous and striated appearance of the oedematous wall can be identified. Pressure of the transducer on the oedematous wall usually reveals easy compressibility. Scrotal wall thickening is usually symmetric and can be greater than 13 mm. In cases of AISE, examination of testes and paratesticular tissues should be unremarkable. [1, 4, 5, 6] Colour Doppler technique is crucial to differentiate testicular torsion from other diseases. In the case of AISE, it reveals the so-called “fountain sign” which refers to the scrotal wall hypervascularity. It is created by multiple vascular branches of the deep external pudendal and internal pudendal arteries which reach the scrotum via the scrotal arteries. These branches arise from a single area and extend towards the scrotal wall in a pattern resembling a fountain. [1] Other less specific ultrasonographic findings of AISE include mild reactive hydrocele and enlarged inguinal lymph nodes with increased vascularity. [2]
AISE can be treated with NSAIDs and antibiotics and normally heals after 3 to 5 days. An unnecessary surgical operation can be avoided thanks to early diagnosis with ultrasonography. [2, 6]
Differential Diagnosis List
Acute idiopathic scrotal oedema combined with sliding testis and cryptorchidism.
Acute idiopathic scrotal oedema
Testicular torsion
Epididymitis
Cellulitis
Torsion of a testicular appendage
Lymphatic malformation
Henoch-Schönlein purpura
Final Diagnosis
Acute idiopathic scrotal oedema combined with sliding testis and cryptorchidism.
Case information
URL: https://eurorad.org/case/13077
DOI: 10.1594/EURORAD/CASE.13077
ISSN: 1563-4086
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