A case of ultrasound diagnosis of retroperitoneal lesion caused by unnoticed foreign body ingestion

We report the case of a 52-year-old patient who was initially admitted to the District Hospital's Surgery Ward with strong abdominal pain. The patient's medical history before the hospitalization was unremarkable. The man did not recall any worrisome situations before the onset of pain. During the hospital stay, he underwent an ultrasound scan, computed tomography and magnetic resonance imaging evaluations, and laboratory tests suggesting that paraduodenal abscess or gastrointestinal stromal tumor should be considered. The patient was referred to the provincial hospital in order to undergo endoscopic ultrasonography. This was when a retroperitoneal foreign body, a toothpick, was found and removed.