title: Retroperitoneal perforation of duodenal ulcers with abscess formation. Report of four cases and survey of the literature.
mesh_terms: D000006:Abdomen, Acute / Q000209:etiology; D000038:Abscess / Q000209:etiology*; D000368:Aged; D004381:Duodenal Ulcer / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010439:Peptic Ulcer Perforation / Q000150:complications* / Q000175:diagnosis; D012187:Retroperitoneal Space; D014839:Vomiting / Q000209:etiology