Is that... a Meckel's diverticulum?!

Clinical History

A 52-year-old male patient was admitted to the emergency department with constant, progressive, right iliac fossa pain during the last 3 days. Blood tests revealed mild leukocytosis and slightly increased PCR.
The patient was referred for an ultrasound exam with suspicion of acute appendicitis.

Imaging Findings

Plain abdominal radiography was unremarkable (Fig.1).

Abdominal ultrasound showed a linear highly hyperchogenic image within an apparent terminal ileum loop, in a fixed transverse position, compatible with a foreign body (Fig. 2).

Further evaluation with abdominal computerized tomography (CT) was suggested and a non-contrast scan revealed linear hyperdense image measuring about 5cm, apparently located in the terminal ileum loop, which seemed to perforate the wall. A normal appendix was detected in the common location. Focal inflammatory changes were present. No free abdominal fluid or air was depicted (Fig. 3).

The diagnosis of terminal ileum loop perforation by a foreign body was suggested.

Based on imaging findings an emergency surgical intervention was performed. Exploratory laparoscopy of the abdomen identified a foreign body (fish bone) perforating a Meckel’s diverticulum that was seen approximately 75 cm proximal to the ileocecal valve (Fig. 4). Histological examination confirmed the diagnosis.

Discussion

Swallowing of foreign bodies (FB) is a common phenomenon in clinical practice, especially among children, elderly and those with dentures or poor mental status [1]. Their passage through the gastrointestinal tract is usually spontaneous and asymptomatic, however perforation can occur in <1% of ingested materials, especially if they are long and sharp-edged. Known perforating agents include chicken and fish bones, toothpicks and dentures [2]. Even after the diagnosis is made, most patients do not recall ingesting a FB [3].
The impaction locations are usually the points of physiological angulation or narrowing within the digestive tract, with the ileocecal region being the most common site of perforation (up to 83% of all cases) [3].

Meckel’s diverticulum is the most common congenital abnormality of the gastrointestinal tract, which is seen in about 2% of adult population, predominantly in males [4]. It consists of a small outpouching of the small intestine due to the incomplete obliteration of the omphalomesenteric duct [5]. Its point of attachment to the bowel varies, but most are found within 100cm of the ileocecal valve. Despite its frequency, complications only occur in 4-16% of cases and includes gastrointestinal haemorrhage (most common), small-bowel obstruction, inflammation, perforation and neoplasia [6]. Perforation by a swallowed foreign body is a rare and unusual complication, with total number of 300 cases being reported in the literature. It has been associated with many bizarre foreign bodies, including chicken bone, bay leaf, wood splinter, melon seeds, and fish bone [7].

Confirming what Charles Mayo stated: "Meckel’s diverticulum is frequently suspected, often looked for, but seldom found" [8], less than 10% of symptomatic Meckel’s diverticula are diagnosed preoperatively, with acute appendicitis being the most common preoperative diagnosis [5].

Despite its irrefutable difficulty to diagnose both clinically and radiologically, as the symptoms and imaging features are non-specific, perforation of Meckel's diverticulum must remain a differential diagnosis in the management of right iliac fossa pain and should be considered in anyone with unexplained abdominal complaints [7]. Plain radiography, ultrasound and CT can be normal or show non-specific changes. On CT, Meckel’s diverticulum usually resembles a normal bowel loop, however a narrow-necked diverticulum can occasionally be identified. The suggestive diagnosis features include abnormal calcifications images related to the foreign body, soft tissue stranding, bowel obstruction, free air or free peritoneal fluid [9]. Definitive treatment is surgical intervention [6].

Differential Diagnosis List

Final Diagnosis

Perforation of Meckel's diverticulum by a foreign body (fish bone)

URL:	https://www.eurorad.org/case/14420
DOI:	10.1594/EURORAD/CASE.14420
ISSN:	1563-4086