A rare cause of painful right inguinal area tumefaction

Clinical History

A 40 year-old man was admitted in the emergency department for rapidly progressive pain in the right lower abdominal quadrant. There was no erythema, or abdominal distension and body temperature was 38,5 C°. Clinical examination revealed a firm painful tumefaction right inguinal area. Laboratory examination result shows leukocytosis (15 600 with 82% neutrophils).

Imaging Findings

A contrast-enhanced CT was performed, showing a mass in the right groin. A blind-ended tubular structure with enhancing and thickened wall was found within this mass .This structure closely related to the tract, appeared normal. The remaining gastro intestinal tract appeared normal, with no evidence of obstruction or dilatation.

Discussion

Protrusion of a vermiform appendix in an inguinal hernia sac is named after Claudius Amyand, the first surgeon who described and treated it [1-3]. Many case reports of these rare hernias have been published. Although most papers consist of a single unique case, Kaymakci et al. [4] published the largest series in 2009 [1-3].The pathophysiology of Amyand’s hernia is unknown [5], it is proposed that appendix in hernia becomes inflamed as a result of repeated trauma, leading to adhesions and bacterial overgrowth [1, 5]. Amyand’s hernias are mostly incidentally discovered during hernia repair [2, 5], and are classically described to occur in 1% appendicitis [1-3, 6].
The clinical presentation is very similar to that of a strangulated inguinal hernia, and thus it is difficult to diagnose clinically [1-3, 6, 7]. The differential diagnosis includes strangulated hernia, strangulated omentocele, Richter’s hernia, inguinal adenitis, orchiepididymitis, incompletely descended testis, acute epididymitis, testicular tumour with haemorrhage, and acute hydrocele [3].
Preoperative diagnosis of Amyand’s hernia, is feasible with ultrasound and CT [1, 3, 6, 7]. Only two cases are presented in literature where diagnosis was established prior to surgery [8, 9]. Ultrasound often demonstrates a potentially inflammatory mass within the hernial sac. The ultrasound image is that of a blind-ended tubular structure with thickened walls in connection with the cecum inside the hernia sac.
CT allows direct visualization of the appendix inside the inguinal canal. Even if this is not possible, location of the cecum in proximity to the hernia sac is indicative of Amyand’s hernia [3, 10, 11]. MPR is most useful in order to better visualise the appendix and demonstrating its relationship with surrounding structures. It aids in confidently making the right diagnosis pre-operatively [3], enabling the surgeon to successfully combine both appendectomy and hernia repair. Amyand’s hernia has also been diagnosed incidentally with barium enema [12]. Preoperative imaging allows some understanding of the situation of the appendix inside the hernia: fluid in the right scrotum, heterogenic tissue oedema on ultrasound, and gas on C Tare probably indicative of perforation [3].

Teaching Points
Aymand’s hernia is a rare condition in which multi detector CT with MPR proves to be a most useful tool in order to establish a correct and early diagnosis in patients presenting with a right lower quadrant syndrome, presenting with or without clinically evident inguinal hernia, inflammatory symptoms and without signs of bowel obstruction.

Differential Diagnosis List

Final Diagnosis

Amyand’s hernia: inguinal hernia with acute appendicitis

URL:	https://www.eurorad.org/case/12402
DOI:	10.1594/EURORAD/CASE.12402
ISSN:	1563-4086