Epididymo-orchitis in a cryptorchidic testis presenting clinically as acute appendicitis

Clinical History

A 48-year-old man was attended at the emergency department for right iliac fossa pain and groin pain for the past 2 days. It increased with deep palpation. He had undergone surgery of cryptorchidism in childhood. He reported dysuria and fever a week before and had therefore undergone antibiotic treatment (amoxicillin/clavulanic acid) with improvement until now.

Imaging Findings

Figure 1. Ultrasound (US) image.
a. Increased echogenicity mass (arrows) with an ill-defined hypoechoic central region (asterisks).
b. Asymmetry caused by inflammatory changes in the right DIR.
c. Minimum ascites surrounding loops (arrowheads) reactive to inflammatory changes of DIR.
d. Colour Doppler US at the hypoechoic region: low resistance arterial and venous flow indicate that it is a solid mass (probably testis tissue) and not a cyst or an abscess.
Figure 2. Sequential CT-images.
Inflammatory changes around bowel (white arrowheads) in continuity with a thickened vas deferens (black arrowheads) and with the nodular mass (arrows) in DIR. Findings were interpreted as orchitis within a cryptorchid testis.
Figure 3. Correlation axial US (a) and CT images (b).
Inflammatory mass in DIR (arrows) with swelling of the adjacent rectus muscles (asterisks).
Figure 4. Curved (a) and sagittal oblique (b) CT reconstructions.
Normal appendix (arrows) originating from caecum (asterisk). There are no inflammatory changes around the appendix.

Discussion

Discussion:
Orchiepididymitis is a common inflammatory and infectious process of the testis and the epididymis. Both are enlarged and painful. High fever may exist. The most common cause is infectious cystitis disseminated through vas deferens and spermatic cord to epididymis and testis. Ultrasound imaging shows an enlarged or reduced epididymis and testis depending on the evolution of the disease over time. Regarding to orchitis, testicular echogenicity can be heterogeneous or decreased. Testicular colour Doppler blood flow can be increased in acute orchitis (testicular hell) and its spectral analysis can show a low resistance arterial curve. Commonly, there are reactive inflammatory changes of the surrounding tissue [1].
Testes originate in the retroperitoneum and migrate caudally through the deep inguinal ring, the inguinal canal and the superficial inguinal ring to finally reach the scrotum.
The undescended testicle may be located anywhere in this path, but the most common location is the internal inguinal ring [1, 2]. Usually they are smaller and iso/hypoechoic than testes located in a normal position. It may be affected by the same infectious and inflammatory processes of a testis located in the scrotal sac [3].
In our case, the inflamed cryptorchid testis, located in the right deep inguinal ring, was clinically interpreted as an acute appendicitis. The previous week urinary tract infection episode and the personal antecedents of operated cryptorchidism were keys to explain the imaging findings, and to suggest the final diagnosis. Initial clinical diagnosis of acute appendicitis was also rejected by imaging tests.
A surgical resection of the inflammatory mass in the right deep inguinal ring was carried out.
Histopathological examination of the surgical specimen showed severe inflammatory and necrotic changes, remnants of vas deferens (it suggests that specimen was composed of cryptorchid testis tissue), fat and muscle tissue.
Very few reported cases of orchitis in undescended testes in adults exist [4-7] and all of them are clinically oriented towards more common processes (appendicitis [4], complicated inguinal hernia [5], etc).
We must keep this entity in mind in a patient with an inflammatory process in the descending route of the testis during embryonic life, essentially when it is located in the deep inguinal ring. We must even investigate a possible cryptorchidism that may have not been initially reported by the patient [6]. A high index of suspicion is crucial to suggest this unusual diagnosis.

Differential Diagnosis List

Final Diagnosis

Acute epididymo-orchitis in an undescended testicle.

URL:	https://www.eurorad.org/case/11572
DOI:	10.1594/EURORAD/CASE.11572
ISSN:	1563-4086