Allergy to metallic stent in a patient with pancreatic carcinoma: case report

Abstract

A 74-year-old man was referred to our hospital for additional treatment of obstructive jaundice. An expandable metallic stent (EMS) was inserted for palliation of the biliary stricture following diagnosis as carcinoma in the pancreatic head. Eight days after stenting, he suffered from high fever and appetite loss. Peripheral blood examination revealed slight anemia. Emergency endoscopy was performed because injury of the duodenal mucosa caused by EMS dislocation was suspected. Esophagogastroduodenoscopy revealed severe edema and small ulcers in the duodenum, mainly around the ampullae. Subsequent CT showed edematous change in the second portion of the duodenum and around the bile duct. We attributed the allergic change to the EMS: after its immediate removal, methyl prednisolone (125 mg/day) was administered. A biopsied specimen from edematous duodenal mucosa showed infiltration of many eosinophils. A skin patch test indicated cobalt allergy. The EMS includes cobalt-containing alloys. Our diagnosis, therefore, was a metal allergy to the indwelling EMS. Although metal allergy to the EMS in the bile duct is extremely rare, it must be considered as a possible complication when using indwelling EMS for obstructive jaundice.