Toothpick perforation of the transverse colon mimicking Crohn\'s disease

Clinical History

Patient with positive family history for Crohn's disease reported abdominal pain, weight loss and fever of three weeks duration. He had no recollection of foreign body ingestion. Clinical and laboratory examinations revealed palpatory tenderness in the supraumbilical area of the abdomen, anaemia, leukocytosis and elevated CRP values.

Imaging Findings

Plain abdominal film revealed no significant roentgenological abnormality (Fig.1). An ultrasound of the abdomen revealed a transverse colon wall thickening with adjacent inhomogenous, hypoechoic structure of ill-defined borders which was mostly oedematous mesenterial fat, fluid and debris (Fig.2). These findings, together with clinical history, were suggestive of Crohn's disease. Ultrasound also revealed a hyperechoic line adjacent to the thickened bowel wall (Fig.2) so we needed further diagnostic evaluation.
Contrast enhanced computed tomography (CT) of the abdomen showed an extraluminal pus collection and a small amount of extraluminal air in the mid abdomen adjacent to the transverse colon with surrounding mesenteric inflammatory stranding. Small linear hyperdense structure was seen in sections within the pus collection (Fig.3).
The patient underwent an open surgery and a wooden toothpick perforation of the transverse colon with mesocolon abscess formation was confirmed (Fig.4). A transverse colon resection was performed with end to end anastomosis.

Discussion

Foreign body ingestion mostly occurs in children, alcoholics, mentally handicapped and edentulous people wearing dentures. In most cases foreign objects pass the gastrointestinal tract without complications [1]. Small percentage perforates the bowel causing complication such as peritonitis, localized abscess formation, enterovesical fistula, intestinal obstruction and intestinal haemorrhage. Sharp foreign objects such as fishbone, chicken bones, toothpicks as well as dentures are known agents that can cause bowel perforation. The majority of perforations occur at narrowing and angulations [2]. The most common sites of perforations are ileocaecal junction, sigmoid colon, appendix, colonic flexure, diverticulae and the anal sphincter.
Symptoms of foreign body bowel perforation are diffuse or localized abdominal pain, nausea, vomiting and fever. Diagnosis of toothpick injury can be difficult as patients are rarely aware of foreign body ingestion, there are no specific physical findings or laboratory examinations and even imaging studies are of little help as wooden toothpicks are radiolucent.
Plain radiographic study usually does not identify wooden objects such as toothpicks. Abdominal ultrasound demonstrates swallowed wooden toothpicks as a hyperechoic, thin, straight line, or a hyperechoic dot. CT is a valuable method for detecting wooden objects but given their small diameter, wooden toothpicks can easily be missed if a high index of suspicion is not present. CT is useful in localization of perforation, revealing bowel wall thickening and evaluating the extent of intra-abdominal inflammation either with or without abscess formation and in excluding findings requiring surgical intervention [3]. Although small amounts of loculated extraluminal air can be seen on CT images, free air in the abdomen is not a common finding [4].
Toothpick injury to the gastrointestinal tract is often associated with considerable morbidity and mortality because it can lead to peritonitis, abscesses, fistulas, migration of toothpicks to adjacent extra-colonic structures and intractable bleeding [4]. Patients, who develop such complications, undergo surgical intervention and it usually involves resection of the bowel with end to end anastomosis.
Abdominal pain and unexplained long lasting fever in a young, previously healthy man with no recollection of foreign body ingestion can be misleading in the diagnostic procedure. Therefore it is important to have high clinical suspicion in such cases. Wooden toothpick is not radiopaque and we were not able to see it on the plain film but it was visualized by CT and ultrasound of the abdomen which makes these procedures valuable tools in making a preoperative diagnosis.

Differential Diagnosis List

Final Diagnosis

Wooden toothpick perforation of the transverse colon with abscess formation

URL:	https://www.eurorad.org/case/11565
DOI:	10.1594/EURORAD/CASE.11565
ISSN:	1563-4086