Funiculitis and epididymitis: an exceptional, unexpected CT diagnosis

Clinical History

A middle-aged man with previous history of urolithiasis complained of left-sided pelvic pain radiating to the ipsilateral flank and groin, associated with fever (up to 39°C), relieved by paracetamol. Physical examination confirmed left lower quadrant tenderness without peritonism.
Laboratory disclosed increased C-Reactive Protein (24mg/L) and urinalysis changes suggested urinary infection.

Imaging Findings

The attending surgeon and urologist requested urgent abdomino-pelvic CT, with or without intravenous contrast at the radiologist’s discretion, to investigate clinical suspicion of acute renal colic, pyelonephritis or sigmoid diverticulitis. On unenhanced CT images (Fig.1) subtle thickening of left ductus deferens was noted, associated with enlarged ipsilateral spermatic cord outside the inguinal canal, thickening and inhomogeneity in the upper scrotum. After intravenous contrast (Fig.2) the thickened spermatic cord and epididymis showed tubular enhancement.
To further investigate these uncommon CT findings, scrotal colour Doppler ultrasound (Fig.3) was performed. The enlarged left epidydimis appeared inhomogeneously hypoechoic, hypervascularised without retrograde flow in the pampiniform plexus or modifications under Valsalva manoeuvre.
Ultimately, blood and urine cultures diagnosed Escherichia coli infection. Serology and urine samples excluded mycobacterial, gonorrhoea, Chlamydia and HIV infections. Combined antibiotic therapy allowed prompt clinical improvement.

Discussion

The commonest cause of scrotal inflammation in adults, acute epididymitis (AE) has a bimodal distribution with the majority of cases occurring between 16-30 and 51-70 years of age. AE results from sexually transmitted Chlamydia trachomatis or Neisseria gonorrhoeae infection in young men, or from retrograde ascent of common aerobic urinary pathogens (such as Escherichia coli) in other groups. Risk factors include sexual activity, strenuous exercise (particularly bike or motorcycle riding), and prolonged sitting [1, 2].
Clinical presentation couples gradual onset of pain, localised to the testis and sometimes radiating to the groin or lower abdomen, with fever and other symptoms of urinary infection, more or less pronounced scrotal swelling and tenderness at physical examination. Laboratory tests, urethral swab and cultures help to direct antibiotic treatment, which cures infection, relieves symptoms, prevents complications and transmission [1, 2].
Ultrasound including colour Doppler is the preferred modality to investigate acute scrotal complaints, particularly to differentiate inflammatory conditions from testicular torsion. In AE sonography shows segmental or global epidydimal enlargement reaching up to 30mm in transverse diameter, inhomogeneously hypoechoic compared to the testis, commonly associated with thickening of scrotal tunicae or hydrocele. Colour Doppler evidence of hyperaemia yields a diagnostic sensitivity approaching 100%. Occasionally inflammatory swelling and hypervascularization involve the spermatic cord, thus resulting in funicolitis [1-3].
Unenhanced CT is currently established as the most accurate technique to investigate urolithiasis and acute renal colic, with the use of intravenous contrast reserved for patients with clinical, laboratory or imaging suspicion of renal infection. Furthermore, CT allows detecting alternative disorders which clinically mimic renal colic. Up to one third (9-29%) of unenhanced CT studies disclose additional or unsuspected findings, most commonly gynaecological conditions (such as haemorrhagic ovarian cysts, adnexal torsion or masses, hydrosalpinx or tubo-ovarian abscess), non-lithiasis genitourinary diseases (particularly pyelonephritis, sometimes renal infarction, haemorrhage, or tumour, hydroureteronephrosis from bladder carcinoma or ureteropelvic junction obstruction), gastrointestinal diseases (appendicitis, omental infarction, or colonic diverticulitis). Pleuropulmonary changes, hepatobiliary (particularly cholelithiasis or acute cholecystitis), vascular, or musculoskeletal abnormalities may occasionally be observed [4, 5].
As this case exemplifies, sometimes CT abnormalities are very subtle, or lie at the borders of the scanned body region. Funicolitis enters the differential diagnosis of groin tenderness or swelling, and should be suspected on the basis of asymmetric thickening or vascular engorgement of the spermatic cord, and appropriately investigated with colour Doppler ultrasound [6, 7].

Differential Diagnosis List

Final Diagnosis

Acute epididymitis with associated funiculitis.

URL:	https://eurorad.org/case/11377
DOI:	10.1594/EURORAD/CASE.11377
ISSN:	1563-4086