Intended for healthcare professionals

Education And Debate

Radiographs and aluminium: a pitfall for the unwary

BMJ 1994; 308 doi: (Published 07 May 1994) Cite this as: BMJ 1994;308:1226
  1. D M Bradburn,
  2. H F Carra,
  3. I Renwick
  1. Department of Surgery, Medical School, Newcastle upon Tyne NE2 4HH.
  2. aDepartments of Surgery and Radiology, Middlesbrough General Hospital, Middlesbrough, Cleveland TS5 5AZ
  1. Correspondence to: Dr
  • Accepted 30 November 1993

Ingestion of radio-opaque foreign bodies is common. We highlight the need for a careful radiological examination and endoscopy if symptoms of obstruction persist.

Case report

A 70 year old man presented to the local hospital while on holiday, having accidentally swallowed part of the metallic tab of a soft drinks can. He complained of retrosternal discomfort and pain on swallowing. Plain radiographs of the chest and neck showed no foreign body and he was consequently discharged.

On returning home he consulted his general practitioner, who referred him to another accident and emergency department, where plain radiographs again showed no abnormality. After four months of persistent retrosternal discomfort and progressive dysphagla he was referred for endoscopy, which showed a malignant looking ulcer 22 cm from the incisors. Biopsy showed no evidence of malignancy, and five further endoscopies over the subsequent three months confirmed a progressive, clinically malignant, stricture, although results on biopsy, oesophageal brushing, and needle cytology did not show any malignancy. A barium swallow examination showed the typical shouldered appearance of a malignant stricture (figure), and computed tomography showed a mass consistent with an oesophageal carcinoma. A small linear opacity was noted in the stricture in one image only, but this was thought to be indistinguishable from oral contrast medium.

In view of his progressive dysphagia a three stage oesophagogastrectomy was performed. There was a hard thickening in the oesophagus, with a surrounding soft swelling and two adjacent lymph nodes. Subsequent pathological examination of the specimen showed an oesophageal diverticulum containing part of a tab of a soft drinks can. There was no evidence of malignancy.


Patients commonly attend accident and emergency departments because they have swallowed a foreign body, but the problems they experience are few as most objects pass through the gastrointestinal tract without incident.1 Impaction in the oesophagus is, however, serious and may result in perforation and even death if missed. Items of food are the commonest foreign bodies in adults, while shiny objects, such as coins, are commoner in children.1 Tabs of soft drink cans are unusual foreign bodies, having been reported in children2 but not, to our knowledge, in adults.

Oesophageal impaction may be suspected clinically from dysphagia and retrosternal discomfort, and initial management should include inspection of the oropharynx and radiography of the neck and chest if the foreign body is thought to be radio-opaque. A delay in diagnosis may result in an abscess, strictures, perforation, or even death, and our case shows that normal results in a chest radiograph cannot be considered adequate to exclude oesophageal impaction of an aluminium foreign body.3,4 Aluminium has a low radiodensity, but this fact was not widely known in a straw poll among our colleagues.

The minimal thickness of steel detectable in vivo is 0.12 mm, and aluminium is 10 times less absorptive. The average thickness of an aluminium ring pull is 0.35 mm, so it is unlikely to be detected in a face on projection. Anteroposterior and lateral projections have therefore been advocated.3 If symptoms persist but no foreign body has been identified endoscopy should be a manadatory part of the investigation.